SSAS
– SSRS is getting a makeover to have a modern look, mobile experience,all browser compatibility, paramater layout customization, new visualizations.
– R modules will be able to execute in SQL Server, moving the analytics code close to the data.
– SSIS designer support for previous versions.
– Power Query support in SSIS.
– Power BI Q&A through the SSAS on-premises data connector.
– Pin SSRS reports to PowerBI dashboards.
– Many to Many relationships on SSAS Tabular.
– Built-in time intelligence on SSAS Tabular models, new DAX functions, parallel partition processing.
– New scripting language for Tabular model projects.
– Netezza as a native data source for SSAS.
– DBCC instruction support for multidimensional for maintenance related tasks.
– Tight integration and improvements in relation to Sharepoint vNext
Improvements on BI 2016 Features:
– Datazen is available now for any SQL 2008+ Enterprise + SA license holder, should be further integrated with the BI stack by release time.– SSRS is getting a makeover to have a modern look, mobile experience,all browser compatibility, paramater layout customization, new visualizations.
– R modules will be able to execute in SQL Server, moving the analytics code close to the data.
– SSIS designer support for previous versions.
– Power Query support in SSIS.
– Power BI Q&A through the SSAS on-premises data connector.
– Pin SSRS reports to PowerBI dashboards.
– Many to Many relationships on SSAS Tabular.
– Built-in time intelligence on SSAS Tabular models, new DAX functions, parallel partition processing.
– New scripting language for Tabular model projects.
– Netezza as a native data source for SSAS.
– DBCC instruction support for multidimensional for maintenance related tasks.
– Tight integration and improvements in relation to Sharepoint vNext
1. Difference between Control Flow and Data Flow
AUDIT: Adds Package and Task level Metadata - such as Machine Name, Execution Instance, Package Name, Package ID, etc.
CHARACTER MAP: When it comes to string formatting in SSIS, Character Map transformation is very useful, used to convert data lower case, upper case.
CONDITIONAL SPLIT: used to split the input source data based on condition.
COPY COLUMN: Add a copy of column to the output, we can later transform the copy keeping the original for auditing.
DATA CONVERSION: Converts columns data types from one to another type. It stands for Explicit Column Conversion.
DATA MINING QUERY: Used to perform data mining query against analysis services and manage Predictions Graphs and Controls.
DERIVED COLUMN: Create a new (computed) column from given expressions.
EXPORT COLUMN: Used to export Image specific column from the database to a flat file.
FUZZY GROUPING: Groups the rows in the dataset that contain similar values.
FUZZY LOOKUP: Used for Pattern Matching and Ranking based on fuzzy logic.
IMPORT COLUMN: Reads image specific column from database onto a flat file.
LOOKUP: Performs the lookup (searching) of a given reference object set to a data source. It is used to find exact matches only.
MULTI CAST: is used to create/distribute exact copies of the source dataset to one or more destination datasets.
ROW COUNT: Stores the resulting row count from the data flow / transformation into a variable.
ROW SAMPLING - Captures sample data by using a row count of the total rows in dataflow specified by rows or percentage.
UNION ALL: Merge multiple data sets into a single dataset.
PIVOT: Used for Normalization of data sources to reduce analomolies by converting rows into columns
UNPIVOT: Used for demoralizing the data structure by converts columns into rows in case of building Data Warehouses.
2.3 Go to Child Package and create a variable with same name as your parent package variable.
2.6 Click 'Next' button and select the 'Value' property of the child package variable.
Click OK to save the changes in the property page.
Right click the package within Solution Explorer and select Execute Package option from the drop down menu.
1. How do u implement Cascading parameter?
="javascript:void(window.open('http://servername/reportserver?%2fpathto%2freport&rs:Command=Render&ProductCode="+Fields!ProductCode.Value+"'))"
1. The total time to generate a report (RDL) can be divided into 3 elements:
Time to retrieve the data (TimeDataRetrieval)
Time to process the report (TimeProcessing)
Time to render the report (TimeRendering)
Total time = (TimeDataRetrieval) + (TimeProcessing) + (TimeRendering)
These 3 performance components are logged every time for which a deployed report is executed. This information can be found in the table ExecutionLogStorage in the ReportServer database.
SELECT TOP 10 Itempath, parameters,
TimeDataRetrieval + TimeProcessing + TimeRendering as [total time],
TimeDataRetrieval, TimeProcessing, TimeRendering,
ByteCount, [RowCount], Source, AdditionalInfo
FROM ExecutionLogStorage
ORDER BY Timestart DESC
2. Use the SQL Profiler to see which queries are executed when the report is generated. Sometimes you will see more queries being executed than you expected. Every dataset in the report will be executed. A lot of times new datasets are added during building of reports. Check if all datasets are still being used. For instance, datasets for available parameter values. Remove all datasets which are not used anymore.
3. Sometimes a dataset contains more columns than used in the Tablix\list. Use only required columns in the Dataset.
4. ORDER BY in the dataset differs from the ORDER BY in the Tablix\list. You need to decide where the data will be sorted. It can be done within SQL Server with an ORDER BY clause or in by the Reporting server engine. It is not useful to do it in both. If an index is available use the ORDER BY in your dataset.
5. Use the SQL Profiler to measure the performance of all datasets (Reads, CPU and Duration). Use the SQL Server Management Studio (SSMS) to analyze the execution plan of every dataset.
6. Avoid dataset with result sets with a lot of records like more than 1000 records. A lot of times data is GROUPED in the report without a Drill down option. In that scenario do the group by already in your dataset. This will save a lot of data transfer to the SQL Server and it will save the reporting server engine to group the result set.
7. Rendering of the report can take a while if the result set is very big. Look very critical if such a big result set is necessary. If details are used in only 5 % of the situations, create another report to display the details. This will avoid the retrieval of all details in 95 % of the situations.
Image Source : External
When you use an external image in a report, the image source is set to External and the value for the image is the URL to the image.
When to Use:
When images are stored in a File System, External File Share or Web Site.
Image Source : Database
If we add images that are stored in a database to report then such image is known as a data-bound image. Data-bound images can also be displayed from binary data (BLOB) stored in a database.
When to use:
When image is stored in a Database.
When you specify a dataset field that is bound to a database field that contains an image.
3. Click OK.
To keep a static tablix member (row or column) visible while scrolling
1. On the design surface, click the row or column handle of the tablix data region to select it. The Grouping pane displays the row and column groups.
2. On the right side of the Grouping pane, click the down arrow, and then clickAdvanced Mode. The Row Groups pane displays the hierarchical static and dynamic members for the row groups hierarchy and the Column groups pane shows a similar display for the column groups hierarchy.
3. Click the static member (row or column) that you want to remain visible while scrolling. The Properties pane displays the Tablix Member properties.
4. In the Properties pane, set FixedData to True.
20. How to add Page Break
1. On the design surface, right-click the corner handle of the data region and then click Tablix Properties.
21. A main report contain subreport also. Can we export both main report and subreport to Excel?
2.1.Right-click the report project, and then click Properties.
2.2.In the Property Pages dialog box for the project, select a configuration to edit from the Configuration list. Common configurations are DebugLocal, Debug, and Release.
2.3.In StartItem, select a report to display in the preview window or in a browser window when the report project is run.
2.4.In the OverwriteDataSources list, select True to overwrite the shared data source on the server each time shared data sources are published, or select False to keep the data source on the server.
2.5.In the TargetDataSourceFolder text box, type the folder on the report server in which to place the published shared data sources. The default value for TargetDataSourceFolder is Data Sources. If you leave this value blank, the data sources will be published to the location specified in TargetReportFolder.
2.6. In the TargetReportFolder text box, type the folder on the report server in which to place the published reports. The default value for TargetReportFolder is the name of the report project.
2.7. In the TargetServerURL text box, type the URL of the target report server. Before you publish a report, you must set this property to a valid report server URL.
3. There are 2 options for deploying the reports that you create with Report Builder 3.0:
1. Report Manager
2. SharePoint document library
45. Report Extensions?
46. parent grouping, child grouping in SSRS
47. How to show "No Data Found" Message to end user?
Add a Text box with expression =IIF(Count(<ID Field>, "DataSet")=0,"No Data Returned", nothing)
and set the visibility of this Text box as =IIF(Count(<ID Field>, "DataSet")=0,False,True)
Open the data source dialog in report designer, and select the "Use Single Transaction when processing the queries' check box. Once selected, datasets that use the same data source are no longer executed in parallel. They are also executed as a transaction, i.e. if any of the queries fails to execute, the entire transaction is rolled back.
The order of the dataset execution sequence is determined by the top-down order of the dataset appearance in the RDL file, which also corresponds to the order shown in report designer.
49. ReportServer and ReportServerTempDB Databases
ReportServer: hosts the report catalog and metadata.
For eg: keeps the catalog items in the Catalog table, the data source information in the Data-Source table of ReportServer Database.
ReportServerTempDB: used by RS for caching purposes.
For eg: once the report is executed, the Report Server saves a copy of the report in the ReportServerTempDB database.
1. Star Vs Snowflake schema and Dimensional modeling
Star Schema: One Fact Table surrounded by number of Dimension Tables. It is a De-Normalized form.
Dimension table will not have any parent table.
Hierarchies in the Dimension are stored in the Dimension itself.
Snowflake: Normalized form of star schema is a snow flake schema. Dimension tables can be further broken down into sub dimensions.
Dimension table will have one or more parent tables.
Hierarchies are broken into separate tables in snow schema. These hierarchies helps to drilldown the data from Top hierarchy to lowermost hierarchy.
Increases the number of joins and poor performance in retrival of data.
2. Data storage modes - MOLAP, ROLAP, HOLAP
In ROLAP, the structure of aggregation along with the values are stored in the 2 dimensional relational formats at disc level.
ROLAP offers low latency, but it requires large storage space as well as slower processing and query response times.
In MOLAP, the structure of aggregation along with the data values are stored in multi dimensional format, takes more space with less time for data analysis compared to ROLAP.
MOLAP offers faster query response and processing times, but offers a high latency and requires average amount of storage space. This storage mode leads to duplication of data as the detail data is present in both the relational as well as the multidimensional storage.
In HOLAP, structure is stored in Relational model and data is stored in multi-dimensional model which provides optimal usage and space.
This storage mode offers optimal storage space, query response time, latency and fast processing times.
Default storage setting is MOLAP.
3. Types of Dimensions
Semi-Additive Facts: These are facts which can be added across only few dimensions rather than all dimensions.
Non-Additive Facts: These are facts which cannot be added across any of the dimensions in the cube. For example, profit margin is a fact which cannot be added across any of the dimensions.
Derived Facts: Derived facts are the facts which are calculated from one or more base facts, often by applying additional criteria. Often these are not stored in the cube and are calculated on the fly at the time of accessing them. For example, profit margin.
Factless Facts: A factless fact table is one which only has references (Foreign Keys) to the dimensions and it does not contain any measures. These types of fact tables are often used to capture events (valid transactions without a net change in a measure value).
Textual Facts: Textual facts refer to the textual data present in the fact table, which is not measurable (non-additive), but is important for analysis purposes. For example, codes (i.e. product codes), flags (i.e. status flag), etc.
5. Types of relationships between dimensions and measure groups.
No relationship: The dimension and measure group are not related.
Regular: The dimension table is joined directly to the fact table.
Referenced: The dimension table is joined to an intermediate table, which in turn, is joined to the fact table.
Many to many: The dimension table is joined to an intermediate fact table, the intermediate fact table is joined, in turn, to an intermediate dimension table to which the fact table is joined.
Data mining: The target dimension is based on a mining model built from the source dimension. The source dimension must also be included in the cube.
Fact table: The dimension table is the fact table.
6. Proactive caching
Proactive caching can be configured to refresh the cache (MOLAP cache) either on a pre-defined schedule or in response to an event (change in the data) from the underlying relational database. Proactive caching settings also determine whether the data is queried from the underlying relational database (ROLAP) or is read from the outdated MOLAP cache, while the MOLAP cache is rebuilt.
Lazy processing option can be changed by server level property "OLAP\LazyProcessing\Enabled"
9. Dimension, Hierarchy, Level, and Members
Dimensions in Analysis Services contain attributes that correspond to columns in dimension tables. These attributes appear as attribute hierarchies and can be organized into user-defined hierarchies, or can be defined as parent-child hierarchies based on columns in the underlying dimension table. Hierarchies are used to organize measures that are contained in a cube.
Hierarchy: is the relation between attributes in a dimension.
Level: refers to individual attribute within the Hierarchy.
10. Difference between database dimension and cube dimension
When you create a dimension using dimension wizard in BIDS, then you're creating a Database dimension in your AS database. Database dimensions is independent of cube and can be processed on their own.
18. How will you keep measure in cube without showing it to user?
19. How to pass parameter in MDX
Here is an example, suppose this is your query:
select {[Measures].[Internet Order Quantity]} on 0,
[Product].[Category].[Category] on 1
from [Adventure Works]
where [Date].[Calendar Year].&[2002]
You can modify it like this:
select {[Measures].[Internet Order Quantity]} on 0,
[Product].[Category].[Category] on 1
from [Adventure Works]
where strtomember(@P1)
Now, if you pass the value [Date].[Calendar Year].&[2002] to the P1, then it will run just like:
where [Date].[Calendar Year].&[2002]
STRTOSET returns a set.
STRTOMEMBER returns a member.
20. SSAS 2008 vs SSAS 2012
21. Dimension security vs Cell security
22. SCOPE statement, THIS keyword, SUBCUBE
23. CASE (CASE, WHEN, THEN, ELSE, END) statement, IF THEN END IF, IS keyword, HAVING clause
24. CELL CALCULATION and CONDITION clause
25. RECURSION and FREEZE statement
26. Common types of errors encountered while processing a dimension / measure groups / cube
27. Logging and monitoring MDX scripts and cube performance
MDX
1.Control flow consists of one or more tasks and containers that execute when the package runs. We use precedence constraints to connect the tasks and containers in a package. SSIS provides three different types of control flow elements:
Containers that provide structures in packages,
Tasks that provide functionality, and
Precedence Constraints that connect the executables, containers, and tasks into an ordered control flow.
2.Control flow does not move data from task to task.
3.Tasks are run in series if connected with precedence or in parallel.
1. A Data flow consists of the sources and destinations that extract and load data, the transformations that modify and extend data, and the paths that link sources, transformations, and destinations. The Data Flow task is the executable within the SSIS package that creates, orders, and runs the data flow. Data Sources, Transformations, and Data Destinations are the three important categories in the Data Flow.
2. Data flows move data, but there are also tasks in the control flow, as such, their success or Failure effects how your control flow operates
3. Data is moved and manipulated through transformations.
Containers that provide structures in packages,
Tasks that provide functionality, and
Precedence Constraints that connect the executables, containers, and tasks into an ordered control flow.
2.Control flow does not move data from task to task.
3.Tasks are run in series if connected with precedence or in parallel.
1. A Data flow consists of the sources and destinations that extract and load data, the transformations that modify and extend data, and the paths that link sources, transformations, and destinations. The Data Flow task is the executable within the SSIS package that creates, orders, and runs the data flow. Data Sources, Transformations, and Data Destinations are the three important categories in the Data Flow.
2. Data flows move data, but there are also tasks in the control flow, as such, their success or Failure effects how your control flow operates
3. Data is moved and manipulated through transformations.
4. Data is passed between each component in the data flow.
2. What are the different types of Transformations you have worked?
AGGEGATE: The Aggregate transformation applies aggregate functions to column values and copies the results to the transformation output. Besides aggregate functions, the transformation provides the GROUP BY clause, which you can use to specify groups to aggregate across.
2. What are the different types of Transformations you have worked?
AGGEGATE: The Aggregate transformation applies aggregate functions to column values and copies the results to the transformation output. Besides aggregate functions, the transformation provides the GROUP BY clause, which you can use to specify groups to aggregate across.
The Aggregate Transformation supports following operations:
Group By, Sum, Average,
Group By, Sum, Average,
Count, Count Distinct, Minimum, Maximum
AUDIT: Adds Package and Task level Metadata - such as Machine Name, Execution Instance, Package Name, Package ID, etc.
CHARACTER MAP: When it comes to string formatting in SSIS, Character Map transformation is very useful, used to convert data lower case, upper case.
CONDITIONAL SPLIT: used to split the input source data based on condition.
COPY COLUMN: Add a copy of column to the output, we can later transform the copy keeping the original for auditing.
DATA CONVERSION: Converts columns data types from one to another type. It stands for Explicit Column Conversion.
DATA MINING QUERY: Used to perform data mining query against analysis services and manage Predictions Graphs and Controls.
DERIVED COLUMN: Create a new (computed) column from given expressions.
EXPORT COLUMN: Used to export Image specific column from the database to a flat file.
FUZZY GROUPING: Groups the rows in the dataset that contain similar values.
FUZZY LOOKUP: Used for Pattern Matching and Ranking based on fuzzy logic.
IMPORT COLUMN: Reads image specific column from database onto a flat file.
LOOKUP: Performs the lookup (searching) of a given reference object set to a data source. It is used to find exact matches only.
MERGE - Merges two sorted data sets of same column structure into a single output.
MERGE JOIN: Merges two sorted data sets into a single dataset using a join.
MERGE JOIN: Merges two sorted data sets into a single dataset using a join.
MULTI CAST: is used to create/distribute exact copies of the source dataset to one or more destination datasets.
ROW COUNT: Stores the resulting row count from the data flow / transformation into a variable.
ROW SAMPLING - Captures sample data by using a row count of the total rows in dataflow specified by rows or percentage.
UNION ALL: Merge multiple data sets into a single dataset.
PIVOT: Used for Normalization of data sources to reduce analomolies by converting rows into columns
UNPIVOT: Used for demoralizing the data structure by converts columns into rows in case of building Data Warehouses.
3. What are Row Transformations, Partially Blocking Transformation, Fully Blocking Transformation with examples.
In Row Transformation, each value is manipulated individually. In this transformation, the buffers can be re-used for other purposes like following: OLEDB Data source, OLEDB Data Destinations, Other Row transformation within the package, Other partially blocking transformations within the package. Examples: Copy Column, Audit, Character Map
Partially Blocking Transformation:
These can re-use the buffer space allocated for available Row transformation and get new buffer space allocated exclusively for Transformation.
Example: Merge, Conditional Split, Multicast, Lookup, Import, Export Column
Fully Blocking Transformation:
It will make use of their own reserve buffer and will not share buffer space from other transformation or connection manager.
Example: Sort, Aggregate, Cache Transformation
4. Difference between Merge and UnionAll Transformations?
The Union All transformation combines multiple inputs into one output. The transformation inputs are added to the transformation output one after the other; no reordering of rows occurs.
Merge Transformations combines two sorted data sets of same column structure into a single output.The rows from each dataset are inserted into the output based on values in their key columns.
The Merge transformation is similar to the Union All transformations.
Use the Union All transformation instead of the Merge transformation in the following situations:
-The Source Input rows are not need to be sorted.
-The combined output does not need to be sorted.
-when we have more than 2 source inputs.
5. Multicast, Conditional Split, Bulk Insert Tasks
Multicast Transformation is used to extract output from single source and places onto multiple destinations.
Conditional Split transformation is used for splitting the input data based on a specific condition. The condition is evaluated in VB Script.
Multicast Transformation generates exact copies of the source data, it means each recipient will have same number of records as the source whereas the Conditional Split Transformation divides the source data based on the defined conditions and if no rows match with this defined conditions those rows are put on default output.
Bulk Insert Task is used to copy the large volume of data from text file to sql server destination.
6. Explain Audit Transformation ?
It allows you to add auditing information. Auditing options that you can add to transformed data through this transformation are :
1. Execution of Instance GUID : ID of execution instance of the package
2. PackageID : ID of the package
3. PackageName : Name of the Package
4. VersionID : GUID version of the package
5. Execution StartTime
6. MachineName
7. UserName
8. TaskName
9. TaskID : unique identifier type of the data flow task that contains audit transformation.
7. Difference between Synchronous and Asynchronous Transformation
Synchronous T/F process the input rows and passes them onto the data flow one row at a time. Synchronous Transformation cannot create new buffer.
When the output buffer of Transformation creates a new buffer, then it is Asynchronous transformation. Output buffer or output rows are not sync with input buffer.
8.Difference between DTS and SSIS?
DTS:
Limited number of transformations.
Limited error handling.
Message box in active-x scripts.
SSIS:
More number of transformations.
Better error handling.
Message box in .NET scripting.
9. How would you pass a Parent variable value to Child Package?
We can pass the parent variable to child package by using Package configuration: Parent Package Variable.
2.1 Create parent variable:
FilePath - Parent - String - C:\RK\file.txt
2.2 Drag an 'Execute Package Task' in Control Flow and configure it to start child package.
2.3 Go to Child Package and create a variable with same name as your parent package variable.
2.4 Add Package configurations
2.5 "Enable Package Configuration", choose Configuration type as "Parent Package Variable" and type the name of the variable.
2.6 Click 'Next' button and select the 'Value' property of the child package variable.
2.7 click 'Next' and 'OK' buttons
2.8 To test the package, I added sample Script Task with a messageBox to show the value of the parent package.
10. My Source Table data as follows:
Output Should be as follows:
How to Implement?
Designed SSIS package like:
The script component code:
11. My Source Table Data as follows:
Output should be as follows:
How to Implement?
12. The data in the Flat File as follows:
"132","Ramesh"," " ,"Hyderabad"
"132","Radhika","17","Vangara"
How to remove double quotes from the file to process the data.
In the Flat File Connection Manager Editor, Enter double quotes in Text Qualifier text box:
13. Will trigger fire when inserting data through SSIS package?
1. In the data flow task, go to the Advanced Editor of OLEDB Destination, and there should be a property "FastLoadOptions". Specify FIRE_TRIGGERS as an additional option.
2. SQL Destination Editor:
3. Bulk Insert Task Editor:
14. What are the different types of Transaction Options?
Required: If a transaction already exists at the upper level, the current executable will join the transaction. If No transaction at the upper level, a new transaction is created automatically.
Supported: In any executable, if there is a transaction at upper level, the executable join the transaction else do not create a new transaction.
Not Supported: The executable of the package do not honor any transaction ie do not join other transaction nor creates new transaction.
15. Explain about Checkpoints with properties
Checkpoint is used to restart the package execution from the point of failure rather than from initial start.
Set the following Properties:
CheckpointFileName: Specifies the name of the checkpoint file.
CheckpointUsage: Never, IfExists, Always
SaveCheckpoints: indicates whether the package needs to save checkpoints. This property must be set to True to restart a package from a point of failure.
FailPackageOnFailure: property needs to be set to True for enabling the task in the checkpoint.
Checkpoint mechanism uses a Text File to mark the point of package failure.
These checkpoint files are automatically created at a given location upon the package failure and automatically deleted once the package ends up with success.
16. How to execute SSIS Package from Stored Procedure.
using xp_cmdshell command
17. How to enable Xp_CmdShell in Sql Server?
We can enable through either T-Sql or SQL Server Surface Area Configuration.
- To allow advanced options to be changed.
EXEC sp_configure 'show advanced options', 1
GO
- To update the currently configured value for advanced options.RECONFIGURE
GO
- To enable the feature.
EXEC sp_configure 'xp_cmdshell', 1
GO
- To update the currently configured value for this feature.
RECONFIGURE
GO
18. Package configuration? Different types of Configuration Files
The package can be transferred across various environments like Development, QA, UAT and production. Most packages will have environment specific variables like connection string to a database or path to a flat file, or user defined variables etc. that would be impacted while moving the package across environments as part of deployment process. Hence, it is mandatory to change these environment dependent variables when the package is transferred across environments. Package configurations help in managing such changes without actually opening and editing the SSIS package in BIDS. After deploying the package to a different machine (using SQL Server or file system deployment mode) it is mandatory to copy the related package configuration files on to that machine. If the package is scheduled to run through a SQL Agent job, the configuration file should be added while creating the job so that package will read the information from the configuration file. While executing the job, SQL Agent will take the design time values for connection strings if the package configuration file is not supplied.
There are 5 configuration types available with package configurations.
19. Logging. Different types of Logging files?
Logging is used to log the information during the execution of package.
A log provider can be a text file, the SQL Server Profiler, a SQL Server relational database, a Windows event log, or an XML file. If necessary, you can define a custom log provider (e.g., a proprietary file format).
20. What is the LoggingMode property?
SSIS packages, tasks and containers have a property called LoggingMode.
This property accepts 3 possible values:
Enabled: to enable logging of that component
Disabled: to disable logging of that component
UseParentSetting: to use parent's setting of that component to decide whether or not to log the data.
21. How to debug a package
For debugging a package, we have 3 options:
-Setting breakpoints in a package, container or Task
-Using Data Viewer in the Data flow task
-Setting Error redirection in the Data Flow task
22. Error handling in SSIS package
I have created a package like below:
Select 'Load to sql Table' Data flow Task. Navigate to 'Even Handlers' Tab.
Drag and Drop 'Execute Sql Task'.
Open the Execute Sql Task Editor and in Parameter Mapping' section, select the system variables as follows:
create a table in Sql Server Database with Columns as: PackageID, PackageName, TaskID, TaskName,
ErrorCode, ErrorDescription.
The package will be failed during the execution.
The error information is inserted into Table.
23. How to configure Error Output in SSIS
we have 3 options to configure error output in ssis.
1. Ignore Failure
2. Redirect Row
3. Fail Component
For Example:
I have comma-separated value in a flat file with two columns (code, Name). Code is an integer value and name is a varchar(20) data type configured in the flat file connection manager. Some of the codes in the flat files are characters. So, flat file reader component will fail reading the character value. But, I want to redirect the error data to separate table.
24. What is Ignore Failure option in SSIS?
In Ignore Failure option, the error will be ignored and the data row will be directed to continue on the next transformation.
Let’s say you have some JUNK data (wrong type of data) flowing from source, then using this option in SSIS we can REDIRECT the junk data records to another transformation instead of FAILING the package. This helps to MOVE only valid data to destination and JUNK can be captured into separate file.
25. Incremental Load in SSIS
Using Slowly Changing Dimension
Using Lookup and Cache Transformation
26. How to migrate Sql server 2005 Package to 2008 version
1. In BIDS, by right click on the "SSIS Packages" folder of an SSIS project and selecting "Upgrade All Packages".
2. Running "ssisupgrade.exe" from the command line (default physical location C:\Program Files\Microsoft SQL Server\100\DTS\Bin folder).
3. If you open a SSIS 2005 project in BIDS 2008, it will automatically launch the SSIS package upgrade wizard.
27. Difference between File System and Sql server Deployment
File System Deployment: We can save the package on a physical location on hard drive or any shared folder with this option, and we should provide a full qualified path to stored package in the FileSystem option.
Sql Server Deployment: SSIS packages will be stored in the sysssispackages table of MSDB Database.
28. Difference between Lookup and Fuzzy Lookup transformation
Lookup Transformation finds the exact match.
Fuzzy Lookup transformation matches input table with reference table. It finds the closest match and indicates the quality of the match.
29. Difference between Full Cache and Partial Cache
Partial Cache: The lookup cache starts off empty at the beginning of the data flow. When a new row comes in, the lookup transform checks its cache for the matching values. If no match is found, it queries the database. If the match is found at the database, the values are cached so they can be used the next time a matching row comes in.
Full Cache: The default cache mode for lookup is Full cache. The database is queried once during the pre-execute phase of the data flow. The entire reference set is pulled into memory. This approach uses most of the memory. Caching takes place before any rows are read from the data flow source. Lookup operations will be very fast during execution.
30. Cache Transformation
Cache Transformation: to cache the data used in the Lookup transform.
When to use Full cache mode:
When you're accessing a large portion of your reference set
When you have a small reference table
When your database is remote or under heavy load, and you want to reduce the number of queries sent to the server
When to use Partial cache mode:
When you're processing a small number of rows and it's not worth the time to charge the full cache.
When you have a large reference table.
When your data flow is adding new rows to your reference table.
When you want to limit the size of your reference table by modifying query with parameters from the data flow.
31. Explain Slowly Changing Dimension
The SCD concept is basically about how the data modifications are absorbed and maintained in a Dimension Table.
The new (modified) record and the old record(s) are identified using some kind of a flag like say IsActive, IsDeleted etc. or using Start and End Date fields to indicate the validity of the record.
Types:
Type 1: update the columns in the dimension row without preserving any change history.
Type 2: preserve the change history in the dimension table and create a new row when there are changes.
Type 3: some combination of Type 1 and Type 2, usually maintaining multiple instances of a column in the dimension row; e.g. a current value and one or more previous values.
32. Different types of File Enumerators
Foreach ADO:
The ADO Enumerator enumerates rows in a table. For example, we can get the rows in the ADO records. The variable must be of Object data type.
Foreach ADO.NET Schema Rowset:
The ADO.Net Enumerator enumerates the schema information. For example, we can get the table from the database.
Foreach File:
The File Enumerator enumerates files in a folder.
For example, we can get all the files which have the *.txt extension in a windows folder and its sub folders.
Foreach From Variable:
The Variable Enumerator enumerates objects that specified variables contain. Here enumerator objects are nothing but an array or data table.
Foreach Item:
The Item Enumerator enumerates the collections.
For example, we can enumerate the names of executable and working directories that an “Execute Process” task uses.
Foreach Nodelist:
The Node List Enumerator enumerates the result of an XPath expression.
Foreach SMO:
The SMO Enumerator enumerates SQL Server Management Objects (SMO). For example, we can get the list of functions or views in a SQL Server database.
33. How to execute the package from .NET?
We need a reference to Microsoft.SqlServer.ManagedDts.dll to call a package.
using Microsoft.SqlServer.Dts.Runtime
Application app = new Application();
Package package = null;
package = app.LoadPackage(@"C:\Program Files\Microsoft SQL Server\100\DTS\Packages\Integration Services Project2\Package.dtsx", null);
Microsoft.SqlServer.Dts.Runtime.DTSExecResult results = package.Execute();
34. How to schedule a package (Role of Sql Server Agent)
In order for the job to run successfully, the SQL Server agent should be running on the target machine.
We can start the SQL Server Agent Services in numerous ways like:-
Starting SQL Server Agent Service from Command Line
• Starting SQL Server Agent Service from Services.MSC console
• Starting SQL Server Agent Service using SQL Server Configuration Manager
• Starting SQL Server Agent Service using SQL Server Management Studio (SSMS)
35. What are containers? (For loop, Sequence Container)
SSIS Containers are controls that provide structure to SSIS packages. Containers support repeating control flows in packages and they group tasks and containers into meaningful units of work. Containers can include other containers in addition to tasks.
Foreach Loop Container: This container runs a Control Flow repeatedly using an enumerator. To repeat tasks for each element in a collection, for example retrieve files from a folder, running T-SQL statements that reside in multiple files, or running a command for multiple objects.
For Loop Container: This container runs a Control Flow repeatedly by checking conditional expression (same as For Loop in programming language). To repeat tasks until a specified expression evaluates to false.
For example, a package can send a different e-mail message seven times, one time for every day of the week.
Sequence Container: Groups tasks as well as containers into Control Flows that are subsets of the package Control Flow. This container group tasks and containers that must succeed or fail as a unit.
For example, a package can group tasks that delete and add rows in a database table, and then commit or roll back all the tasks when one fails.
36. What are precedence constraints?
A task will only execute if the condition that is set by the precedence constraint preceding the task is met. By using these constraints, it will choose different execution paths depending on the success or failure of other tasks.
Success: Workflow will proceed when the preceding container executes successfully. Indicated in control flow by a solid green line.
Failure: Workflow will proceed when the preceding container’s execution results in a failure. Indicated in control flow by a solid red line.
Completion: Workflow will proceed when the preceding container’s execution completes, regardless of success or failure. Indicated in control flow by a solid blue line.
Expression/Constraint with Logical AND: Workflow will proceed when specified expression and constraints evaluate to true. Indicated in control flow by a solid color line along with a small ‘fx’ icon next to it. Color of line depends on logical constraint chosen (e.g. success=green, completion=blue).
Expression/Constraint with Logical OR: Workflow will proceed when either the specified expression or the logical constraint (success/failure/completion) evaluates to true. Indicated in control flow by a dotted color line along with a small ‘fx’ icon next to it. Color of line depends on logical constraint chosen (e.g. success=green, completion=blue).
37. Performance Optimization in SSIS
1. Avoid Asynchronous Transformation (Sort T/F) wherever possible.
Sort T/F required all the incoming rows to be arrived before start processing. Instead of using Sort T/F, we get sorted rows from data source using ORDER By clause.
2. While pulling High Volumes of Data,
Drop all Non-Clustered Indexes and Clustered Index if exists, then Transfer and load the data into Destination Table. Then create Clustered Index and Non-clustered indexes.
3. Avoid SELECT *
Data Flow Task uses buffer oriented architecture for data transfer and transformation. When data transfer from Source to Destination, the data first comes into the buffer; required transformations are done in the buffer itself and then written to Destination.
The size of buffer depends on the estimated row size. The estimated row size is equal to the maximum size of all columns in the row. So the more columns in a row mean less number of rows in a buffer. Hence select only those columns which are required at the destination.
Even if we need all the columns from source, we should use the column name specifically in the SELECT statement.
4. Effect of OLEDB Destination Settings:
There are couples of settings with OLEDB destination which can impact the performance of data transfer.
Data Access Mode: This setting provides the 'fast load' option which internally uses a BULK INSERT statement for uploading data into the destination table instead of a simple INSERT statement (for each single row) as in the case for other options. So unless you have a reason for changing it, don't change this default value of fast load. If you select the 'fast load' option, there are also a couple of other settings which you can use as discussed below.
Keep Identity: By default this setting is unchecked which means the destination table (if it has an identity column) will create identity values on its own. If you check this setting, the dataflow engine will ensure that the source identity values are preserved and same value is inserted into the destination table.
Keep Nulls: Again by default this setting is unchecked which means default value will be inserted (if the default constraint is defined on the target column) during insert into the destination table if NULL value is coming from the source for that particular column. If you check this option then default constraint on the destination table's column will be ignored and preserved NULL of the source column will be inserted into the destination.
Table Lock: By default this setting is checked and the recommendation is to let it be checked unless the same table is being used by some other process at same time. It specifies a table lock will be acquired on the destination table instead of acquiring multiple row level locks, which could turn into lock escalation problems.
Check Constraints: Again by default this setting is checked and recommendation is to un-check it if you are sure that the incoming data is not going to violate constraints of the destination table. This setting specifies that the dataflow pipeline engine will validate the incoming data against the constraints of target table. If you un-check this option it will improve the performance of the data load.
#5 - Effect of Rows Per Batch and Maximum Insert Commit Size Settings:
Rows per batch:
The default value for this setting is -1 which specifies all incoming rows will be treated as a single batch. You can change this default behavior and break all incoming rows into multiple batches. The allowed value is only positive integer which specifies the maximum number of rows in a batch.
Maximum insert commit size:
The default value for this setting is '2147483647' (largest value for 4 byte integer type) which specifies all incoming rows will be committed once on successful completion. You can specify a positive value for this setting to indicate that commit will be done for those number of records. Changing the default value for this setting will put overhead on the dataflow engine to commit several times. Yes that is true, but at the same time it will release the pressure on the transaction log and tempdb to grow specifically during high volume data transfers.
The above two settings are very important to understand to improve the performance of tempdb and the transaction log. For example if you leave 'Max insert commit size' to its default, the transaction log and tempdb will keep on growing during the extraction process and if you are transferring a high volume of data the tempdb will soon run out of memory as a result of this your extraction will fail. So it is recommended to set these values to an optimum value based on your environment.
#7 - DefaultBufferSize and DefaultBufferMaxRows :
The execution tree creates buffers for storing incoming rows and performing transformations.
The number of buffer created is dependent on how many rows fit into a buffer and how many rows fit into a buffer dependent on few other factors.
The first consideration is the estimated row size, which is the sum of the maximum sizes of all the columns from the incoming records.
The second consideration is the DefaultBufferMaxSize property of the data flow task. This property specifies the default maximum size of a buffer. The default value is 10 MB and its upper and lower boundaries are constrained by two internal properties of SSIS which are MaxBufferSize (100MB) and MinBufferSize (64 KB). It means the size of a buffer can be as small as 64 KB and as large as 100 MB.
The third factor is, DefaultBufferMaxRows which is again a property of data flow task which specifies the default number of rows in a buffer. Its default value is 10000.
If the size exceeds the DefaultBufferMaxSize then it reduces the rows in the buffer.
For better buffer performance you can do two things.
First you can remove unwanted columns from the source and set data type in each column appropriately, especially if your source is flat file. This will enable you to accommodate as many rows as possible in the buffer.
Second, if your system has sufficient memory available, you can tune these properties to have a small number of large buffers, which could improve performance. Beware if you change the values of these properties to a point where page spooling begins, it adversely impacts performance. So before you set a value for these properties, first thoroughly testing in your environment and set the values appropriately.
#8 - How DelayValidation property can help you
SSIS uses two types of validation.
First is package validation (early validation) which validates the package and all its components before starting the execution of the package.
Second SSIS uses component validation (late validation), which validates the components of the package once started.
Let's consider a scenario where the first component of the package creates an object i.e. a temporary table, which is being referenced by the second component of the package. During package validation, the first component has not yet executed, so no object has been created causing a package validation failure when validating the second component. SSIS will throw a validation exception and will not start the package execution. So how will you get this package running in this common scenario?
To help you in this scenario, every component has a DelayValidation (default=FALSE) property. If you set it to TRUE, early validation will be skipped and the component will be validated only at the component level (late validation) which is during package execution
9. Better performance with parallel execution
10. When to use events logging and when to avoid.
11. Monitoring the SSIS Performance with Performance Counters
Launch Performance Monitor:
1. Start -> All Programs -> Administrative Tools -> Performance
2. Load the SSIS related Counters
In the Performance Object, select SQL Server:SSIS Pipeline and SQL Server:SSIS Service.
SSIS provide a set of performance counters. Among them, the following few are helpful when you tune or debug your package:
Buffers in use
Flat buffers in use
Private buffers in use
Buffers spooled
Rows read
Rows written
“Buffers in use”, “Flat buffers in use” and “Private buffers in use” are useful to discover leaks. During package execution time, we will see these counters fluctuating. But once the package finishes execution, their values should return to the same value as what they were before the execution. Otherwise, buffers are leaked.
“Buffers spooled” has an initial value of 0. When it goes above 0, it indicates that the engine has started memory swapping. In a case like this, set Data Flow Task properties BLOBTempStoragePath and BufferTempStoragePath appropriately for maximal I/O bandwidth.
Buffers Spooled: The number of buffers currently written to the disk. If the data flow engine runs low on physical memory, buffers not currently used are written to disk and then reloaded when needed.
“Rows read” and “Rows written” show how many rows the entire Data Flow has processed.
12. FastParse property
Fast Parse option in SSIS can be used for very fast loading of flat file data. It will speed up parsing of integer, date and time types if the conversion does not have to be locale-sensitive. This option is set on a per-column basis using the Advanced Editor for the flat file source.
13. Checkpoint features helps in package restarting
38. Upgrade DTS package to SSIS
1. In BIDS, from the Project Menu, select 'Migrate DTS 2000 Package'
2. In the Package Migration Wizard, choose the Source, Sql Server 2000 Server Name, Destination folder.
3. Select the List of packages that needs to be upgraded to SSIS
4. Specifty the Log file for Package Migration.
39. Events in SSIS
OnError : Runs when a task or container reports an error.
OnExecStatusChanged : Runs for all tasks and containers when the execution status changes to In Process, Success, or Failed.
OnInformation : Runs when SSIS outputs information messages during the validation and execution of a task or container.
OnPostExecute : Runs after a container or task successfully completes.
OnPostValidate : Executes after a container or task has successfully been validated.
OnPreExecute : Runs just before a container or task is executed.
OnPreValidate: Runs before the component is validated by the engine.
OnProgress : Executed when a progress message is sent by the SSIS engine, indicating tangible advancement of the task or container.
OnQueryCancel : Invoked when an Execute SQL Task is cancelled through manual intervention, such as stopping the package.
OnTaskFailed : Similar to OnError, but runs when a task fails rather than each time an error occurs.
OnVariableValueChanged: Runs when the value changes in a variable for which the RaiseChangeEvent property is set to True.
OnWarning Runs: when a task returns a warning event such as a column not being used in a data flow.
40. Different ways to execute SSIS package
1. Using the Execute Package Utility (DTEXECUI.EXE) graphical interface one can execute an SSIS package that is stored in a File System, SQL Server or an SSIS Package Store.
DTEXECUI provides a graphical user interface that can be used to specify the various options to be set when executing an SSIS package. You can launch DTEXECUI by double-clicking on an SSIS package file (.dtsx). You can also launch DTEXECUI from a Command Prompt then specify the package to execute.
2. Using the DTEXEC.EXE command line utility one can execute an SSIS package that is stored in a File System, SQL Server or an SSIS Package Store. The syntax to execute a SSIS package which is stored in a File System is shown below.
DTEXEC.EXE /F "C:\BulkInsert\BulkInsertTask.dtsx"
3. Test the SSIS package execution by running the package from SSDT:
In Solution Explorer, right click the SSIS project folder that contains the package which you want to run and then click properties.
In the SSIS Property Pages dialog box, select Build option under the Configuration Properties node and in the right side panel, provide the folder location where you want the SSIS package to be deployed within the OutputPath.
In Solution Explorer, right click the SSIS project folder that contains the package which you want to run and then click properties.
In the SSIS Property Pages dialog box, select Build option under the Configuration Properties node and in the right side panel, provide the folder location where you want the SSIS package to be deployed within the OutputPath.
Click OK to save the changes in the property page.
Right click the package within Solution Explorer and select Execute Package option from the drop down menu.
4. Sql Server Agent:
Drill down to the SQL Server Agent node in the Object Explorer.
Right click on the Jobs node and select New Job from the popup menu.
The first step to setting up the proxy is to create a credential (alternatively you could use an existing credential). Navigate to Security then Credentials in SSMS Object Explorer and right click to create a new credential
Navigate to SQL Server Agent then Proxies in SSMS Object Explorer and right click to create a new proxy
41. How to execute a Stored Procedure from SSIS?
using Execute SQL Task
42. How to deploy packages from one server to another server
43. How to deploy a package
Right click on the Solution in Solution Explorer and choose properties in the Menu.
When the build /rebuild is successful, navigate to the directory is referred in DeploymentOutputPath
Deploying the Package:
Double click the Manifest File to start the deployment.
The Package Installation wizard begins and Deploy SSIS Packages step is the first screen that is presented.
This screen lets you select where shall the packages be deployed, as mentioned in the Dialog Box, deploying in SQL Server is more secure, since SQL Server stores the packages internally compared to File System where additional security measures needs to taken to secure the physical files.
44. What is the use of Percentage Sampling transformation in SSIS?
Percentage Sampling transformation is generally used for data mining. This transformation builds a random sample of set of output rows by choosing specified percentage of input rows. For example if the input has 1000 rows and if I specify 10 as percentage sample then the transformation returns 10% of the RANDOM records from the input data.
45. What is the use of Term Extraction transformation in SSIS?
Term Extraction transformation is used to extract nouns or noun phrases or both noun and noun phrases only from English text. It extracts terms from text in a transformation input column and then writes the terms to a transformation output column. It can be also used to find out the content of a dataset.
46. What is Data Viewer and what are the different types of Data Viewers in SSIS?
A Data Viewer allows viewing data at a point of time at runtime.
The different types of data viewers are:
1. Grid
2. Histogram
3. Scatter Plot
4. Column Chart
47. what are the possible locations to save SSIS package?
1.File System: We can save the package on a physical location on hard drive or any shared folder with this option, and we should provide a full qualified path to stored package in the FileSystem option.
2. Sql Server: SSIS packages will be stored in the MSDB database, in the sysssispackages table.
SSIS Package Store is nothing but combination of SQL Server and File System deployment, as you can see when you connect to SSIS through SSMS: it looks like a store which has categorized its contents (packages) into different categories based on its manager’s (which is you, as the package developer) taste. So, don’t get it wrong as something different from the 2 types of package deployment.
48. How to provide security to packages?
We can provide security to packages in 2 ways
1. Package encryption
2. Password protection
1. DonotSaveSensitive: any sensitive information is simply not written out to the package XML file when you save the package.
2. EncryptSensitiveWithUserKey: encrypts sensitive information based on the credentials of the user who created the package. It is the default value for the ProtectionLevel property.
3. EncryptSensitiveWithPassword: requires to specify a password in the package, and this password will be used to encrypt and decrypt the sensitive information in the package.
4. EncryptAllWithPassword: allows to encrypt the entire contents of the SSIS package with your specified password.
5. EncryptAllWithUserKey: allows to encrypt the entire contents of the SSIS package by using the user key.
6. Server Storage: allows the package to retain all sensitive information when you are saving the package to SQL Server. SSIS packages are saved to MSDB database of SQL Server.
You can change the Protection Level of deployed packages by using the DTUTIL utility.
49. How to track a variable in ssis?
OnVariableValueChanged: This event gets raised when value of the variable is changed.
1. Set the "EvaluateasExpression" property of the variable as True.
2. Set the "RaiseChangedEvent" property of the variable as True.
3. Create an event handler for the "OnVariableValueChanged" event for the container in which the variable is scoped.
50. FTP Task:
The FTP task downloads and uploads data files and manages directories on servers. For example, a package can download data files from a remote server.
use the FTP task for the following purposes:
1. Copying directories and data files from one directory to another, before or after moving data, and applying transformations to the data.
2. Downloading files from an FTP location and applying transformations to column data before loading the data into a database.
At run time, the FTP task connects to a server by using an FTP connection manager. The FTP connection manager includes the server settings, the credentials for accessing the FTP server, and options such as the time-out and the number of retries for connecting to the server.
The FTP connection manager supports only anonymous authentication and basic authentication. It does not support Windows Authentication.
Predefined FTP Operations:
Send Files, Receive File,
Create Local directory, Remove Local Directory,
Create Remote Directory, Remove Remote Directory
Delete Local Files, Delete Remote File
Customer Log Entries available on FTP Task:
FTPConnectingToServer
FTPOperation
51. New features in SSIS 2012
1. GUI Improvements - -Sort packages by name -Package visualization -Zoom -Data flow source/destination wizard -Grouping in data flow
2. CDC (Change Data Capture) Task and Components -
-CDC is nothing but Incremental load loads all rows that have changed since the last load
-CDC needs to keep track of which changes have already been processed.
-CDC task does this by storing LSNs in a tracking table -CDC source component reads from the CDC table function, based on the LSN it for from the CDC task.
-CDC transformation splits records into new rows, updated rows and deleted rows.
3. Flat File Connection Manager Changes -
-The Flat File connection manager now supports parsing files with embedded qualifiers. The connection manager also by default always checks for row delimiters to enable the correct parsing of files with rows that are missing column fields. The Flat File Source now supports a varying number of columns, and embedded qualifiers.
4. Offline Connection Managers: Integration Services now validates all connections before validating all of the data flow components when a package is opened and sets any connections that are slow or unavailable to work offline. This helps to reduce the delay in validating the package data flow. After a package is opened, you can also turn off a connection by right-clicking the connection manager in the Connection Managers area and then clicking Work Offline. This can speed up operations in the SSIS Designer.
5. New Functions/Expressions in SSIS 2012:
LEFT: You now can easily return the leftmost portion of a string rather than use the SUBSTRING function. Left syntax is the same as we know in T-SQL: LEFT(character_expression,number)
REPLACENULL: You can use this function to replace NULL values in the first argument with the expression specified in the second argument. This is equivalent to ISNULL in T-SQL: REPLACENULL(expression, expression)
TOKEN: This function allows you to return a substring by using delimiters to separate a string into tokens and then specifying which occurrence to return: TOKEN(character_expression, delimiter_string, occurrence)
TOKENCOUNT: This function uses delimiters to separate a string into tokens and then returns the count of tokens found within the string:
TOKENCOUNT(character_expression, delimiter_string)
6. Easy Column Remapping in Data Flow (Mapping Data Flow Columns) -When modifying a data flow, column remapping is sometimes needed -SSIS 2012 maps columns on name instead of id -It also has an improved remapping dialog
7. Shared Connection Managers: To create connection managers at the project level that can shared by multiple packages in the project. The connection manager you create at the project level is automatically visible in the Connection Managers tab of the SSIS Designer window for all packages. -When converting shared connection managers back to regular (package) connection managers, they disappear in all other packages.
8. Scripting Enhancements: Now Script task and Script Component support for 4.0. - Breakpoints are supported in Script Component
9. ODBC Source and Destination - -ODBC was not natively supported in 2008 -SSIS 2012 has ODBC source & destination -SSIS 2008 could access ODBC via ADO.NET
10. Reduced Memory Usage by the Merge and Merge Join Transformations – The old SSIS Merge and Merge Join transformations, although helpful, used a lot of system resources and could be a memory hog. In 2012 these tasks are much more robust and reliable. Most importantly, they will not consume excessive memory when the multiple inputs produce data at uneven rates.
11. Undo/Redo: One thing that annoys users in SSIS before 2012 is lack of support of Undo and Redo. Once you performed an operation, you can’t undo that. Now in SSIS 2012, we can see the support of undo/redo.
52. Difference between Script Task and Script Component in SSIS.
Script Task Script Component
Control Flow/Date Flow The Script task is configured on the Control Flow tab of the designer and runs outside the data flow of the package. The Script component is configured on the Data Flow page of the designer and represents a source, transformation, or destination in the Data Flow task.
Purpose A Script task can accomplish almost any general-purpose task. You must specify whether you want to create a source, transformation, or destination with the Script component.
Raising Results The Script task uses both the TaskResult property and the optional ExecutionValue property of the Dts object to notify the runtime of its results. The Script component runs as a part of the Data Flow task and does not report results using either of these properties.
Raising Events The Script task uses the Events property of the Dts object to raise events. For example: Dts.Events.FireError(0, "Event Snippet", ex.Message & ControlChars.CrLf & ex.StackTrace The Script component raises errors, warnings, and informational messages by using the methods of the IDTSComponentMetaData100 interface returned by the ComponentMetaData property. For example: Dim myMetadata as IDTSComponentMetaData100
myMetaData = Me.ComponentMetaData
myMetaData.FireError(...)
Execution A Script task runs custom code at some point in the package workflow. Unless you put it in a loop container or an event handler, it only runs once. A Script component also runs once, but typically it runs its main processing routine once for each row of data in the data flow.
Editor The Script Task Editor has three pages: General, Script, and Expressions. Only the ReadOnlyVariables and ReadWriteVariables, and ScriptLanguage properties directly affect the code that you can write. The Script Transformation Editor has up to four pages: Input Columns, Inputs and Outputs, Script, and Connection Managers. The metadata and properties that you configure on each of these pages determines the members of the base classes that are autogenerated for your use in coding.
Interaction with the Package In the code written for a Script task, you use the Dts property to access other features of the package. The Dts property is a member of the ScriptMain class. In Script component code, you use typed accessor properties to access certain package features such as variables and connection managers. The PreExecute method can access only read-only variables. The PostExecute method can access both read-only and read/write variables.
Using Variables The Script task uses the Variables property of the Dts object to access variables that are available through the task’s ReadOnlyVariables and ReadWriteVariables properties. For example: string myVar; myVar = Dts.Variables["MyStringVariable"].Value.ToString(); The Script component uses typed accessor properties of the autogenerated based class, created from the component’s ReadOnlyVariables and ReadWriteVariables properties. For example: string myVar; myVar = this.Variables.MyStringVariable;
Using Connections The Script task uses the Connections property of the Dts object to access connection managers defined in the package. For example: string myFlatFileConnection; myFlatFileConnection = (Dts.Connections["Test Flat File Connection"].AcquireConnection(Dts.Transaction) as String); The Script component uses typed accessor properties of the autogenerated base class, created from the list of connection managers entered by the user on the Connection Managers page of the editor. For example: IDTSConnectionManager100 connMgr;connMgr = this.Connections.MyADONETConnection;
53. How to execute package from command line
1. To execute an SSIS package saved to SQL Server using Windows Authentication:
dtexec /sq pkgOne /ser productionServer
2. To execute an SSIS package that is saved in the file system:
dtexec /f "c:\pkgOne.dtsx"
3. To execute an SSIS package saved to the File System folder in the SSIS Package Store:
dtexec /dts "\File System\MyPackage"
4. To execute an SSIS package that is saved in the file system and configured externally:
dtexec /f "c:\pkgOne.dtsx" /conf "c:\pkgOneConfig.cfg"
54. How to unzip a File in SSIS?
Use Execute Process Task in the Control Flow.
From BIDS, drag and drop an "Execute Process Task" to the control flow and configure.
In the Execute Process, perform the following configurations:
Executable: The path of the application that is being used.
Arguments: Need to supply the arguments to extract the zipped files.
Working Directory: The current directory for all process.
55. which service requires to start a job?
SQL Server Agent Service
56. Difference between OLEDB Destination, SQL Destination, Bulk Insert
1. OLEDB destination loads the records in batches, whereas SQL Server destination loads all the records at one go.
2. OLEDB Destination uses the 'Fast Load' data access mode.
SQL Server destination uses shared memory for maximum loading speed, must execute on the same server as the database engine.
Prefer the OLE-DB Destination simply because it gives better flexibility on where you execute the package.
3. The Bulk Insert task uses the T-SQL BULK INSERT statement for speed when loading large amounts of data.
57. which services are installed during Sql Server installation?
SSIS
SSAS
SSRS
SQL Server (MSSQLSERVER)
SQL Server Agent Service
SQL Server Browser
SQL Full-Text
58. How to run dynamic T-SQL in SSIS?
Option#1: Using Script Component as Destination
Option#2: Using Object Variable and run t-sql with Execute SQL Task
59. What is the use of RecordSet Destination?
The Recordset destination does not save data to an external data source. Instead, it saves data in memory in a recordset that is stored in variable of the Object data type. After the Recordset destination saves the data, we use a Foreach Loop container with the Foreach ADO enumerator to process one row of the recordset at a time. The Foreach ADO enumerator saves the value from each column of the current row into a separate package variable. Then, the tasks that you configure inside the Foreach Loop container read those values from the variables and perform some action with them.
60. Delay Validation, Forced Execution
Delay Validation: Validation take place during the package execution.
Early Validation: Validation take place just before the package execution.
61. Transfer Database Task
used to move a database to another SQL Server instance or create a copy on the same instance (with different database name). This task works in two modes: Offline, Online.
Offline: In this mode, the source database is detached from the source server after putting it in single user mode, copies of the mdf, ndf and ldf files are moved to specified network location. On the destination server the copies are taken from the network location to the destination server and then finally both databases are attached on the source and destination servers. This mode is faster, but a disadvantage with mode is that the source database will not available during copy and move operation. Also, the person executing the package with this mode must be sysadmin on both source and destination instances.
Online: The task uses SMO to transfer the database objects to the destination server. In this mode, the database is online during the copy and move operation, but it will take longer as it has to copy each object from the database individually. Someone executing the package with this mode must
be either sysadmin or database owner of the specified databases.
62. Transfer SQL Server Object Task
Used to transfer one or more SQL Server objects to a different database, either on the same or another SQL Server instance. You can transfer tables, views, Indexes, stored procedures, User defined functions, Users, Roles etc.
63. How to Generate an Auto Incremental Number in a SSIS Package?
A script component can be used for the designated task. The steps are as follows:
1. Drag and drop the Script Document to the Data flow and select the Script Component Type as Transformation.
2. Double click the Script Component.
3. Select the column which is to pass through the script component, in the Input Columns tab.
4. Add a column with an integer data type, in the Inputs and Outputs tab.
64. Breakpoint in SSIS?
A breakpoint allows you to pause the execution of the package in BIDS during development or when troubleshooting an SSIS Package. You can right click on the task in control flow, click on 'Edit Breakpoint' menu and from the Set Breakpoint window, you specify when you want execution to be halted/paused. For example OnPreExecute, OnPostExecute, OnError events, etc. To toggle a breakpoint, delete all breakpoints and disable all breakpoints go to the Debug menu and click on the respective menu item. You can even specify different conditions to hit the breakpoint as well.
65. What is the DisableEventHandlers property used for?
SSIS packages, tasks and containers have a property called DisableEventHandlers. If you set this property to TRUE for task or container, then all event handlers will be disabled for that task or container. If you set this property value to FALSE then the event handlers will once again be executed.
66. How to create Temporary Table using SSIS?
1. For the connection manager, set the property RetainSameConnection =True so that temporary table created in one Control Flow task can be retained in another task.
RetainSameConnection means that the temp table will not be deleted when the task is completed.
2. Create a data-flow task that consumes your global temp table in an OLE DB Source component.
3. Set DelayValidation=TRUE on the data-flow task, means that the task will not check if the table exists upon creation.
67. How to Lock a variable in Script Task?
public void Main()
{
Variables vars = null ;
bool fireAgain = true;
Dts.VariableDispenser.LockOneForRead("varName", ref vars);
//Do something with the value...
vars.Unlock();
Dts.TaskResult = (int)ScriptResults.Success;
}
68. How to pass property value at Run time?
A property value like connection string for a Connection Manager can be passed to the package using package configurations.
69. How to skip first 5 lines in each Input flat file?
In the Flat file connection manager editor, Set the 'Header rows to skip' property.
70. Parallel processing in SSIS
To support parallel execution of different tasks in the package, SSIS uses 2 properties:
1.MaxConcurrentExecutables: defines how many tasks can run simultaneously, by specifying the maximum number of SSIS threads that can execute in parallel per package. The default is -1, which equates to number of physical or logical processor + 2.
2. EngineThreads: is property of each DataFlow task. This property defines how many threads the data flow engine can create and run in parallel. The EngineThreads property applies equally to both the source threads that the data flow engine creates for sources and the worker threads that the engine creates for transformations and destinations. Therefore, setting EngineThreads to 10 means that the engine can create up to ten source threads and up to ten worker threads.
71. How do we convert data type in SSIS?
The Data Conversion Transformation in SSIS converts the data type of an input column to a different data type.
72. One Excel file contains 10 rows. 2nd Excel file contains 10 rows. There are 5 matching rows in both excel. How find non-matched rows from both excel and store in output excel file.
73. Difference between Copy Column and Derived Column Transformations
Both transformations can add new columns.
Copy column can add new columns only through existing columns. Derived column can be used to create new column with or without help of existing columns.
Derived column supports error output whereas Copy column cannot.
74. Let’s say if we have some reference data in Excel and we want to use that excel Data in Lookup Transformation, how we can achieve that without loading into staging or temp table
Cache Transformation
75. I have a source file that contains 1000 records, I want to insert 15% records in TableA and remaining in TableB which transformation I can use?
Percentage Sampling
76. There is no Union Transformation in SSIS, How to perform UNION operation by using built-in Transformation?
77. Before you create your SSIS Package and load data into destination, you want to analyze your data, which task will help you to achieve that?
Data Profiling Task
78. In Merge Join Transformation, we can use Inner Join, Left Join and Full Outer Join; Which Transformation is used to perform Cross Join.
Workaround is to add the Derived Column Transformation to add a new column to each of the two sources that you want to join (call the columns [JoinCol]) and put a literal value (e.g. "1") into that column for every single row. In the Merge Join transform, simply join on the two [JoinCol] columns.
79. Direct Vs. Indirect Configuration in SSIS
Direct configuration
Pros:
-Doesn't need environment variables creation or maintenance
-Scale well when multiple databases (Test or DEV) are used on the same server
-Changes can be made to the configurations files (.dtsconfig) when deployment is made using SSIS deployment utility
Cons:
-Need to specify configuration file that we want to use when the package is triggered with DTExec (/conf switch).
-If multiple layers of packages are used (parent/child packages), need to transfer configured values from the parent to the child package using parent packages variables which can be tricky (if one parent variable is missing, the rest of the parent package configs (parameters) will not be transferred).
Indirect configuration
Pros:
-All packages can reference the configuration file(s) via environment variable
-Packages can be deployed simply using copy/paste or xcopy, no need to mess with SSIS deployment utility
-Packages or application is not dependent of configuration switches when triggered with DTExec utility (command line is much simpler)
Cons:
-Require environment variables to be created
-Does not support easily multiple databases (TEST and Pre-Prod) to be used on the same server
80. We get the data from flat file and how to remove Leading Zero, Trailing Zeros OR Leading and trailing both before insert into destination.
Use the Derived column Transformation to remove Leading/Trailing OR Both zero from the string. After removing Zeros you can Cast to Any data type you want such as Numeric, Int, float etc.
Leading Zeros: (DT_WSTR,50)(DT_I8)[YourInputColumn]
Trailing Zeros: REVERSE((DT_WSTR,50)(DT_I8)REVERSE([YourInputColumn]))
Leading and Trailing Zeros:
REVERSE((DT_WSTR,50)(DT_I8)REVERSE((DT_WSTR,50)(DT_I8)[YourInputColumn]))
81. Import Data in SSMS:
We can't apply transformations on source data with "Import Data", "Export Data".
Import and Export Wizard in SSIS:
We can apply transformations on source data
82. How do I troubleshoot SSIS packages failed execution in SQL Agent job?
When you see a SSIS package fails running in a SQL Agent job, you need to first consider the following conditions:
1. The user account that is used to run the package under SQL Server Agent differs from the original package author.
2. The user account does not have the required permissions to make connections or to access resources outside the SSIS package.
The following 4 issues are common encountered in the SSIS forum.
1. The package's Protection Level is set to EncryptSensitiveWithUserKey but your SQL Server Agent service account is different from the SSIS package creator.
2. Data source connection issue.
3. File or registry access permission issue.
4. No 64-bit driver issue.
Package Protection Level issue:
For the 1st issue, you can follow the following steps to troubleshoot this issue:
1. Check what the Protection Level is in your SSIS package.
2. If the Protection Level is set to EncryptSensitiveWithUserKey, check the Creator in your SSIS package and compare it with the SQL Server Agent Service account.
3. If the Creator is different from the SQL Server Agent Service account, then the sensitive data of the SSIS package could not be correctly decrypted, which will lead to the failure.
A common solution to this issue is that you create a proxy account for SSIS in SQL Server Agent and then specify the proxy account as the "Run as" account in the job step. The proxy account must be the same as the SSIS package creator.
You can also change the SSIS package protection level to EncryptSensitiveWithPassword and specify the password in the command line in the job step.
Data Source Connection Issue:
It happens when you are using Windows Authentication for your data source. In this case, you need to make sure that the SQL Server Agent Services service account or your Proxy account has the permission to access your database.
83. How to run SSIS Packages using 32-bit drivers on 64-bit machine?
On 64 Operating System when you install Integration Services it will install 32-Bit and 64-Bit version of DTExec commandline tool which is used to execute SSIS packages.
If your SSIS package is referencing any 32-Bit DLL or 32-Bit drivers from your package then you must use 32-Bit version of DTExec to execute SSIS package.
If you have reference to any 32-Bit driver/dll then make sure you change Project Property Run64BitRuntime to False before you Debug your package in BIDS otherwise your package will try to load 64-Bit dlls instead of 32-Bit.
To change this setting
- Right click on Project Node
- Under Debugging option, set Run64BitRuntime=False
SSRS Interview
Questions and Answers
1. How do u implement Cascading parameter?
The list of values for one parameter depends on the value
chosen in preceding parameter.
Eg: Country --> State --> City
2. How to pass parameter from Report
Viewer Control to sub report?
3. How to open another report in a
new window from existing report?
Use a little javascript with a customized URL in the
"Jump to URL" option of the Navigation tab.
Non-parameterized Solution
To get started, let's pop up a simple non parameterized
report. Follow these instructions:
1.
Instead of using the "Jump to
Report" option on the Navigation tab, use the "Jump to URL"
option.
2.
Open the expression screen (Fx
button).
3.
Enter the following:
="javascript:void(window.open('http://servername?%2freportserver%2fpathto%2freport&rs:Command=Render'))"
="javascript:void(window.open('http://servername?%2freportserver%2fpathto%2freport&rs:Command=Render'))"
4.
Click OK twice, then save and deploy
the report.
Parameterized Solution
Assume you have a field called ProductCode. Normally, you
might hard code that like this:
http://servername/reportserver?%2fpathto%2freport&rs:Command=Render&ProductCode=123
In this case, you want to pass variables dynamically,
using an available value from the source dataset. You can think of it like
this:
http://servername/reportserver?%2fpathto%2freport&rs:Command=Render&ProductCode=Fields!ProductCode.Value
The exact syntax in the "Jump to URL" (Fx)
expression window will be:
="javascript:void(window.open('http://servername/reportserver?%2fpathto%2freport&rs:Command=Render&ProductCode="+Fields!ProductCode.Value+"'))"
4. How to pass parameter from chart
to Table in same report?
5. How to apply custom Colors of
chart report?
STEP1:
Create your custom color palette in the report using
Custom Code in your report. To do so, click Report => Report Properties => Code and copy below code:
Private colorPalette As String() = { "Blue",
"Red", "Teal", "Gold",
"Green","#A59D93", "#B8341B",
"#352F26", "#F1E7D6", "#E16C56",
"#CFBA9B"}
Private count As Integer = 0
Private mapping As New System.Collections.Hashtable()
Public Function GetColor(ByVal groupingValue As String) As
String
If mapping.ContainsKey(groupingValue) Then
Return mapping(groupingValue)
End If
Dim c As String = colorPalette(count Mod
colorPalette.Length)
count = count + 1
mapping.Add(groupingValue, c)
Return c
End Function
STEP2:
In the Pie Chart, select Series Properties and select the
Fill option from left side.
Now write following expression in the Color expression:
=code.GetColor(Fields!Year.Value)
Here Fields!Year.Value is a field of dataset which is used
as Chart Category fields.
6. Can we have Table within a
Table in SSRS report?
Yes. We can have Nested Tables.
7. How to apply stylesheet to SSRS
Reports
select Report->Report Properties from the menu
and then click the Code tab.
Function StyleElement (ByVal Element As String) As String
Function StyleElement (ByVal Element As String) As String
Select Case UCase(Element)
Case
"TABLE_HEADER_BG"
Return "Red"
Case
"TABLE_FOOTER_BG"
Return "Green"
Case
"TABLE_HEADER_TEXT"
Return "White"
Case Else
Return "Black”
End Select
End Function
Now apply this function to the style property of an
element on the report.
=code.StyleElement("TABLE_HEADER_TEXT")
If you want apply dynamic styles to report, then create
tables in sql server and insert style information into the tables.
Create a Dataset, specify the Stored Procedure.
example: =Fields!TABLE_HEADER_TEXT.Value where
TABLE_HEADER_TEXT is a value in the table.
8. Dynamic sorting, Dynamic Grouping
in SSRS
Can be done using expressions.
9. Different types of Filters
The 2 types of filters in SSRS are:
Dataset Filter: Filtering
within the source query. When you implement a filter within the data set,
less data is sent from the source database server to the Report Server -
usually a good thing.
Report Filter: This
includes filtering after the source query has come back – on a data region
(like the Tablix), or a data grouping. When you implement a filter within
the report, when the report is re-executed again with different parameter
choices, the Report Server uses cached data rather than returning to the
database server.
Using a Dataset
Filter is the most efficient method.
10. Difference between Filter and
Parameter? Which one is better?
In case of Filters, first the data will be fetched from
the database, then the Filters are applied on the fetched data. Filters are
applied at run time first on the dataset, and then on the data region, and then
on the group, in top-down order for group hierarchies.
To add a filter, we must specify a filter equation
(expression). The data type of filtered data and value must match.
Parameters are applied at the database level. The Data
will be fetched based on parameters at the database level using WHERE condition
in the query.
Parameters are better than Filters in performance.
11. Optimization of Report
Report can be optimized in terms of Grouping, Filters.
Report can be optimized in terms of Grouping, Filters.
Report can be optimized through Caching, Snapshot and
subscriptions.
1. The total time to generate a report (RDL) can be divided into 3 elements:
Time to retrieve the data (TimeDataRetrieval)
Time to process the report (TimeProcessing)
Time to render the report (TimeRendering)
Total time = (TimeDataRetrieval) + (TimeProcessing) + (TimeRendering)
These 3 performance components are logged every time for which a deployed report is executed. This information can be found in the table ExecutionLogStorage in the ReportServer database.
SELECT TOP 10 Itempath, parameters,
TimeDataRetrieval + TimeProcessing + TimeRendering as [total time],
TimeDataRetrieval, TimeProcessing, TimeRendering,
ByteCount, [RowCount], Source, AdditionalInfo
FROM ExecutionLogStorage
ORDER BY Timestart DESC
2. Use the SQL Profiler to see which queries are executed when the report is generated. Sometimes you will see more queries being executed than you expected. Every dataset in the report will be executed. A lot of times new datasets are added during building of reports. Check if all datasets are still being used. For instance, datasets for available parameter values. Remove all datasets which are not used anymore.
3. Sometimes a dataset contains more columns than used in the Tablix\list. Use only required columns in the Dataset.
4. ORDER BY in the dataset differs from the ORDER BY in the Tablix\list. You need to decide where the data will be sorted. It can be done within SQL Server with an ORDER BY clause or in by the Reporting server engine. It is not useful to do it in both. If an index is available use the ORDER BY in your dataset.
5. Use the SQL Profiler to measure the performance of all datasets (Reads, CPU and Duration). Use the SQL Server Management Studio (SSMS) to analyze the execution plan of every dataset.
6. Avoid dataset with result sets with a lot of records like more than 1000 records. A lot of times data is GROUPED in the report without a Drill down option. In that scenario do the group by already in your dataset. This will save a lot of data transfer to the SQL Server and it will save the reporting server engine to group the result set.
7. Rendering of the report can take a while if the result set is very big. Look very critical if such a big result set is necessary. If details are used in only 5 % of the situations, create another report to display the details. This will avoid the retrieval of all details in 95 % of the situations.
12. I have 'State' column in report,
display the States in bold, whose State name starts with letter 'A' (eg: Andhra
pradesh, Assam should be in bold)
13. In which scenario you used Matrix
Report
Use a matrix to display aggregated data summaries, grouped
in rows and columns, similar to a PivotTable or crosstab. The number of rows
and columns for groups is determined by the number of unique values for each row
and column groups.
14. Image control in SSRS
An image is a report item that contains a reference to an
image that is stored on the report server, embedded within the report, or
stored in a database.
Image Source: Embedded
Local report images are embedded in the report and then referenced. When you embed an image, Report Designer MIME-encodes the image and stores it as text in the report definition.
When to Use:
When image is embedded locally within the report.
When you are required to store all images within the report definition.
Image Source: Embedded
Local report images are embedded in the report and then referenced. When you embed an image, Report Designer MIME-encodes the image and stores it as text in the report definition.
When to Use:
When image is embedded locally within the report.
When you are required to store all images within the report definition.
Image Source : External
When you use an external image in a report, the image source is set to External and the value for the image is the URL to the image.
When to Use:
When images are stored in a File System, External File Share or Web Site.
Image Source : Database
If we add images that are stored in a database to report then such image is known as a data-bound image. Data-bound images can also be displayed from binary data (BLOB) stored in a database.
When to use:
When image is stored in a Database.
When you specify a dataset field that is bound to a database field that contains an image.
15. Role of Report Manager
Deploying the reports onto the web server.
Delivering the reports through E-mail or File Share using the
subscriptions.
Creating the Cached and Snapshot Reports.
Providing the Security to the reports.
16. How to upload a report to report
server
In the Report Manager, we have upload option to upload the
reports.
17. What is a Shared Dataset
Shared datasets retrieve data from shared data sources
that connect to external data sources. A shared dataset contains a query to
provide a consistent set of data for multiple reports. The dataset query can
include dataset parameters.
Shared datasets use only shared data sources, not embedded
data sources.
To create a shared dataset, you must use an application
that creates a shared dataset definition file (.rsd). You can use one of the
following applications to create a shared dataset:
1. Report Builder: Use shared dataset design mode and save
the shared dataset to a report server or SharePoint site.
2. Report Designer in BIDS: Create shared datasets under
the Shared Dataset folder in Solution Explorer. To publish a shared dataset,
deploy it to a report server or SharePoint site.
Upload a shared dataset definition (.rsd) file. You can
upload a file to the report server or SharePoint site. On a SharePoint site, an
uploaded file is not validated against the schema until the shared dataset is
cached or used in a report.
The shared dataset definition includes a query, dataset
parameters including default values, data options such as case sensitivity, and
dataset filters.
18. How do u display the partial text
in bold format in textbox in Report? (eg: FirstName LastName, where
"FirstName" should in bold fornt and "LastName" should be
in normal font.)
Use PlaceHolder
19. How to Keep Headers Visible
When Scrolling Through a Report?
1. Right-click the row, column, or corner handle of a tablix data region, and then click Tablix Properties.
2. On the General tab, under Row Headers or Column Headers, select Header should remain visible while scrolling.
1. Right-click the row, column, or corner handle of a tablix data region, and then click Tablix Properties.
2. On the General tab, under Row Headers or Column Headers, select Header should remain visible while scrolling.
3. Click OK.
To keep a static tablix member (row or column) visible while scrolling
1. On the design surface, click the row or column handle of the tablix data region to select it. The Grouping pane displays the row and column groups.
2. On the right side of the Grouping pane, click the down arrow, and then clickAdvanced Mode. The Row Groups pane displays the hierarchical static and dynamic members for the row groups hierarchy and the Column groups pane shows a similar display for the column groups hierarchy.
3. Click the static member (row or column) that you want to remain visible while scrolling. The Properties pane displays the Tablix Member properties.
4. In the Properties pane, set FixedData to True.
20. How to add Page Break
1. On the design surface, right-click the corner handle of the data region and then click Tablix Properties.
2. On the General tab, under Page break options,
select one of the following options:
Add a page break before: Select this
option when you want to add a page break before the table.
Add a page break after: Select this
option when you want to add a page break after the table.
Fit table on one page if possible: Select this
option when you want the data to stay on one page.
21. A main report contain subreport also. Can we export both main report and subreport to Excel?
Yes. The exported report contains both the mail report and
sub report.
22. how to convert PDF report from
Portrait to Landscape format?
In Report Properties -->
Set the width of the report to the landscape size of your
A4 paper: 29.7 cm
Set the height of the report to 21 cm.
To avoid extra blank pages during export, the size of the
body should be less or equal to the size of the report - margins.
Set the width of the body to 26.7 cm (29.7 -1.5 - 1.5)
Set the height of the body to 18 cm (21 - 1.5 -1.5)
23. Error handling in Report
Step 1: All the data sets of the report
should contain one addition input parameter which should pass a unique
information for every request (for every click of View Report button) made by
the user.
Step 2: Need to implement TRY CATCH blocks for all the Stored procedures used in the SSRS reports through datasets. The CATCH section of every procedure should have the provision to save the error details into DB table, if any error occurred while execution of that procedure.
Step 3: Add one more additional dataset with the name "ErrorInfo" which should call the store procedure (USP_ERROR_INFO). This procedure should be accepting a unique value. This unique value should be passed to all the data sets for every click of 'View Report' button made by the user. This dataset will return the error information available in the data base table by verifying records with the unique id which has passes as input parameter.
Step 4:Enable the “Use Single Transaction When Processing Queries” option in data source properties, which makes all the query executions through a single transaction.
Step 5: After successful completion of all the above mentioned steps, insert new table on SSRS report with custom error information which will be shown to the report user if the user gets any error during execution of the report.
Step 2: Need to implement TRY CATCH blocks for all the Stored procedures used in the SSRS reports through datasets. The CATCH section of every procedure should have the provision to save the error details into DB table, if any error occurred while execution of that procedure.
Step 3: Add one more additional dataset with the name "ErrorInfo" which should call the store procedure (USP_ERROR_INFO). This procedure should be accepting a unique value. This unique value should be passed to all the data sets for every click of 'View Report' button made by the user. This dataset will return the error information available in the data base table by verifying records with the unique id which has passes as input parameter.
Step 4:Enable the “Use Single Transaction When Processing Queries” option in data source properties, which makes all the query executions through a single transaction.
Step 5: After successful completion of all the above mentioned steps, insert new table on SSRS report with custom error information which will be shown to the report user if the user gets any error during execution of the report.
24. Have u worked on any 3rd party
Report Tools
There are few third party Report Tools like Nevron,
izenda.
25. Different ways of Deploying
reports
1. We can deploy the reports using rs.exe tool
2. In the Solution Explorer,
1. We can deploy the reports using rs.exe tool
2. In the Solution Explorer,
2.1.Right-click the report project, and then click Properties.
2.2.In the Property Pages dialog box for the project, select a configuration to edit from the Configuration list. Common configurations are DebugLocal, Debug, and Release.
2.3.In StartItem, select a report to display in the preview window or in a browser window when the report project is run.
2.4.In the OverwriteDataSources list, select True to overwrite the shared data source on the server each time shared data sources are published, or select False to keep the data source on the server.
2.5.In the TargetDataSourceFolder text box, type the folder on the report server in which to place the published shared data sources. The default value for TargetDataSourceFolder is Data Sources. If you leave this value blank, the data sources will be published to the location specified in TargetReportFolder.
2.6. In the TargetReportFolder text box, type the folder on the report server in which to place the published reports. The default value for TargetReportFolder is the name of the report project.
2.7. In the TargetServerURL text box, type the URL of the target report server. Before you publish a report, you must set this property to a valid report server URL.
3. There are 2 options for deploying the reports that you create with Report Builder 3.0:
1. Report Manager
2. SharePoint document library
26. Difference between Cached Report
and Snapshot Report
Cached Report is a saved copy of processed report.
The first time a user clicks the link for a report configured to cache, the report execution process is similar to the on-demand process. The intermediate format is cached and stored in ReportServerTempDB Database until the cache expiry time.
The first time a user clicks the link for a report configured to cache, the report execution process is similar to the on-demand process. The intermediate format is cached and stored in ReportServerTempDB Database until the cache expiry time.
If a user requests a different set of parameter values for
a cached report, then the report processor treats the request as a new report
executing on demand, but flags it as a second cached instance.
Report snapshot contains the Query and Layout information
retrieved at specific point of time. It executes the query and produces the
intermediate format. The intermediate format of the report has no expiration
time like a cached instance, and is stored in ReportServer Database.
27. Subscription. Different types of
Subscriptions?
Subscriptions are used to deliver the reports to either
File Share or Email in response to Report Level or Server Level Schedule.
There are 2 types of subscriptions:
1. Standard Subscription: Static properties are set for
Report Delivery.
2. Data Driven Subscription: Dynamic Runtime properties
are set for Subscriptions
28. SSRS Architecture
29. How to deploy Reports from one
server to other server
30. Different life cycles of Report
1.Report authoring:
This stage involves creation of reports that are published
using the Report Definition language. RDL is an XML based industry standard for
defining reports.
Report Designer is a full-featured report authoring tool
that runs in Business Intelligence Development Studio and Report Builder.
2. Report management:
This involves managing the published reports as a part of
the webservice. The reports are cached for consistency and performance. They
can be executed whenever demanded or can be scheduled and executed.
In short Report Management includes:
- Organizing reports and data sources,
- Scheduling report execution and delivery
- Tracking reporting history.
3. Report delivery:
Reports can be delivered to the consumers either on their
demand or based on an event. Then they can view them is a web-based format.
–Web based delivery via Report Manager web site
–Subscriptions allow for automated report delivery
–URL Access, Web Services and Report Viewer control
4.Report security:
It is important to protect reports as well as the report
resources. Therefore, Reporting Services implement a flexible, role-based
security model.
31. Different type of Reports
Linked report: is derived from
an existing report and retains the original's report definition. A linked
report always inherits report layout and data source properties of the original
report. All other properties and settings can be different from those of the
original report, including security, parameters, location, subscriptions, and
schedules.
Snapshot reports: A report snapshot
contains layout information and query results that were retrieved at
a specific point in time. Report snapshots are processed on a schedule and
then saved to a report server.
Sub report: A sub report is a
report that displays another report inside the body of a main report.
The sub report can use different data sources than the main report.
Cached reports: A cached report
is a saved copy of a processed report. Cached reports are used to improve
performance by reducing the number of processing requests to the report
processor and by reducing the time required to retrieve large reports.
They have a mandatory expiration period, usually in minutes.
Drill Down Report: Means
navigate from the summary level to detail level in the same report.
Drill Through Report: Navigation
from one report to another report.
Ad hoc reports: allows the end
users to design and create reports on their own provided the data models.
3 components: Report Builder, Report Model and Model Designer
Use 'Model Designer' tool to design 'Report Models' and then use 'Report Model' tool to generate reports.
Report Builder
- Windows Winform application for End users to build ad-hoc reports with the help of Report models.
32. Explain the Report Model Steps.
3 components: Report Builder, Report Model and Model Designer
Use 'Model Designer' tool to design 'Report Models' and then use 'Report Model' tool to generate reports.
Report Builder
- Windows Winform application for End users to build ad-hoc reports with the help of Report models.
32. Explain the Report Model Steps.
1. Create the report model project
select "Report Model Project" in the Templates list
A report model project contains the definition of the data source (.ds file), the definition of a data source view (.dsv file), and the report model (.smdl file).
2. Define a data source for the report model
3. Define a data source view for the report model
A data source view is a logical data model based on one or more data sources.
SQL Reporting Services generates the report model from the data source view.
4. Define a report model
5. Publish a report model to report server.
select "Report Model Project" in the Templates list
A report model project contains the definition of the data source (.ds file), the definition of a data source view (.dsv file), and the report model (.smdl file).
2. Define a data source for the report model
3. Define a data source view for the report model
A data source view is a logical data model based on one or more data sources.
SQL Reporting Services generates the report model from the data source view.
4. Define a report model
5. Publish a report model to report server.
33. How to get the data for Report
Model Reports
Datasource View
Datasource View
34. Difference between RDL and RDLC?
RDL files are created for Sql Server Reporting Services and .RDLC files are for Visual Studio Report Viewer Component.
The <Query> element of RDL contains query or command and is used by the Report Server to connect to the datasources of the report.
The <Query> element is optional in RDLC file. This element is ignored by Report Viewer control because Report Viewer control does not perform any data processing in Local processing mode, but used data that the host application supplies.
RDL files are created for Sql Server Reporting Services and .RDLC files are for Visual Studio Report Viewer Component.
The <Query> element of RDL contains query or command and is used by the Report Server to connect to the datasources of the report.
The <Query> element is optional in RDLC file. This element is ignored by Report Viewer control because Report Viewer control does not perform any data processing in Local processing mode, but used data that the host application supplies.
35. Difference between Sorting and
Interactive Sorting?
To control the Sort order of data in report, you must set the sort expression on the data region or group. The does not have control over sorting.
You can provide control to the user by adding Interactive Sort buttons to toggle between ascending and descending order for rows in a table or for rows and columns in a matrix. The most common use of interactive sort is to add a sort button to every column header. The user can then choose which column to sort by.
To control the Sort order of data in report, you must set the sort expression on the data region or group. The does not have control over sorting.
You can provide control to the user by adding Interactive Sort buttons to toggle between ascending and descending order for rows in a table or for rows and columns in a matrix. The most common use of interactive sort is to add a sort button to every column header. The user can then choose which column to sort by.
36. What is Report Builder
Windows Winform application for End users to build ad-hoc reports with the help of Report models.
Windows Winform application for End users to build ad-hoc reports with the help of Report models.
37. Difference between Table report and Matrix Report
A Table Report can have fixed number of columns and dynamic rows.
A Matrix Report has dynamic rows and dynamic columns.
38. When to use Table, Matrix and List
1. Use a Table to display detail data, organize the data in row groups, or both.
2. Use a matrix to display aggregated data summaries, grouped in rows and columns, similar to a PivotTable or crosstab. The number of rows and columns for groups is determined by the number of unique values for each row and column groups.
3. Use a list to create a free-form layout. You are not limited to a grid layout, but can place fields freely inside the list. You can use a list to design a form for displaying many dataset fields or as a container to display multiple data regions side by side for grouped data. For example, you can define a group for a list; add a table, chart, and image; and display values in table and graphic form for each group value
A Table Report can have fixed number of columns and dynamic rows.
A Matrix Report has dynamic rows and dynamic columns.
38. When to use Table, Matrix and List
1. Use a Table to display detail data, organize the data in row groups, or both.
2. Use a matrix to display aggregated data summaries, grouped in rows and columns, similar to a PivotTable or crosstab. The number of rows and columns for groups is determined by the number of unique values for each row and column groups.
3. Use a list to create a free-form layout. You are not limited to a grid layout, but can place fields freely inside the list. You can use a list to design a form for displaying many dataset fields or as a container to display multiple data regions side by side for grouped data. For example, you can define a group for a list; add a table, chart, and image; and display values in table and graphic form for each group value
39. Report Server Configuration Files
1. RSReportServer.config:
Stores configuration settings for feature areas of the Report Server service: Report Manager, the Report Server Web service, and background processing.
2. RSSrvPolicy.config
Stores the code access security policies for the server extensions.
3. RSMgrPolicy.config
Stores the code access security policies for Report Manager.
4. Web.config for the Report Server Web service
Includes only those settings that are required for ASP.NET.
5. ReportingServicesService.exe.config
6. Registry settings
7. Web.config for Report Manager
Includes only those settings that are required for ASP.NET
8. RSReportDesigner.config
9. RSPreviewPolicy.config
1. RSReportServer.config:
Stores configuration settings for feature areas of the Report Server service: Report Manager, the Report Server Web service, and background processing.
2. RSSrvPolicy.config
Stores the code access security policies for the server extensions.
3. RSMgrPolicy.config
Stores the code access security policies for Report Manager.
4. Web.config for the Report Server Web service
Includes only those settings that are required for ASP.NET.
5. ReportingServicesService.exe.config
6. Registry settings
7. Web.config for Report Manager
Includes only those settings that are required for ASP.NET
8. RSReportDesigner.config
9. RSPreviewPolicy.config
40. Difference between a Report and
adhoc Report
Ad Hoc reporting allows the end users to design and create reports on their own provided the data models.
Adhoc Report is created from existing report model using Report Builder.
Ad Hoc reporting allows the end users to design and create reports on their own provided the data models.
Adhoc Report is created from existing report model using Report Builder.
41. How do u secure a Report
1. Authorization is provided through a role-based security model that is specific to Reporting Services.
Different Types of Roles provided by SSRS :
- Browsers
- Content Manager
- My Reports
- Publishers
- Report Builder
2. IIS security controls access to the report server virtual directory and Report Manager.
1. Authorization is provided through a role-based security model that is specific to Reporting Services.
Different Types of Roles provided by SSRS :
- Browsers
- Content Manager
- My Reports
- Publishers
- Report Builder
2. IIS security controls access to the report server virtual directory and Report Manager.
42.How to Combine Datasets in SSRS (1
Dataset gets data from Oracle and other dataset from Sql Server)
Using LookUP function, we can combine 2 datasets in SSRS.
In the following example, assume that a table is bound to a dataset that includes a field for the product identifier ProductID. A separate dataset called "Product" contains the corresponding product identifier ID and the product name Name.
=Lookup(Fields!ProductID.Value, Fields!ID.Value, Fields!Name.Value, "Product")
In the above expression, Lookup compares the value of ProductID to ID in each row of the dataset called "Product" and, when a match is found, returns the value of the Name field for that row.
43. Difference between Report Server and Report Manager
Report Server handle authentication, data processing, rendering and delivery operations.
The configuration settings of Report Manager and the Report Server Web service are stored in a single configuration file (rsreportserver.config).
Report Manager is the web-based application included with Reporting Services that handles all aspects of managing reports (deploying datasources and reports, caching a report, subscriptions, snapshot).
44. Steps to repeat Table Headers in SSRS 2008?
1. Select the table
2. At the bottom of the screen, select a dropdown arrow beside column groups. Enable "Advanced Mode" by clicking on it.
3. under Row Groups,select the static row and choose properties / press F4.
4. Set the following attributes for the static row or header row.
Set RepeatOnNewPage= True for repeating headers
Set KeepWithGroup= After
Set FixedData=True for keeping the headers visible.
45. How to add assemblies in SSRS
In the following example, assume that a table is bound to a dataset that includes a field for the product identifier ProductID. A separate dataset called "Product" contains the corresponding product identifier ID and the product name Name.
=Lookup(Fields!ProductID.Value, Fields!ID.Value, Fields!Name.Value, "Product")
In the above expression, Lookup compares the value of ProductID to ID in each row of the dataset called "Product" and, when a match is found, returns the value of the Name field for that row.
43. Difference between Report Server and Report Manager
Report Server handle authentication, data processing, rendering and delivery operations.
The configuration settings of Report Manager and the Report Server Web service are stored in a single configuration file (rsreportserver.config).
Report Manager is the web-based application included with Reporting Services that handles all aspects of managing reports (deploying datasources and reports, caching a report, subscriptions, snapshot).
44. Steps to repeat Table Headers in SSRS 2008?
1. Select the table
2. At the bottom of the screen, select a dropdown arrow beside column groups. Enable "Advanced Mode" by clicking on it.
3. under Row Groups,select the static row and choose properties / press F4.
4. Set the following attributes for the static row or header row.
Set RepeatOnNewPage= True for repeating headers
Set KeepWithGroup= After
Set FixedData=True for keeping the headers visible.
45. How to add assemblies in SSRS
45. Report Extensions?
46. parent grouping, child grouping in SSRS
47. How to show "No Data Found" Message to end user?
Add a Text box with expression =IIF(Count(<ID Field>, "DataSet")=0,"No Data Returned", nothing)
and set the visibility of this Text box as =IIF(Count(<ID Field>, "DataSet")=0,False,True)
48. What is the 'Use single
transaction when processing the queries' in the Datasource? Dataset Execution
Order?
By default, datasets are executed in parallel.
This option used to reduce the amount of open connections
to the database. For example, if you have a report with 3 datasets and
you don’t have this option checked, a new connection is made to the database
for every single dataset. However, if you have it checked, then only one
connection will be open to the database and all the datasets will return the
data and the connection will be closed. This can be used to reduce
network traffic and potentially increase performance.
Open the data source dialog in report designer, and select the "Use Single Transaction when processing the queries' check box. Once selected, datasets that use the same data source are no longer executed in parallel. They are also executed as a transaction, i.e. if any of the queries fails to execute, the entire transaction is rolled back.
The order of the dataset execution sequence is determined by the top-down order of the dataset appearance in the RDL file, which also corresponds to the order shown in report designer.
49. ReportServer and ReportServerTempDB Databases
ReportServer: hosts the report catalog and metadata.
For eg: keeps the catalog items in the Catalog table, the data source information in the Data-Source table of ReportServer Database.
ReportServerTempDB: used by RS for caching purposes.
For eg: once the report is executed, the Report Server saves a copy of the report in the ReportServerTempDB database.
1. Star Vs Snowflake schema and Dimensional modeling
Star Schema: One Fact Table surrounded by number of Dimension Tables. It is a De-Normalized form.
Dimension table will not have any parent table.
Hierarchies in the Dimension are stored in the Dimension itself.
Snowflake: Normalized form of star schema is a snow flake schema. Dimension tables can be further broken down into sub dimensions.
Dimension table will have one or more parent tables.
Hierarchies are broken into separate tables in snow schema. These hierarchies helps to drilldown the data from Top hierarchy to lowermost hierarchy.
Increases the number of joins and poor performance in retrival of data.
2. Data storage modes - MOLAP, ROLAP, HOLAP
In ROLAP, the structure of aggregation along with the values are stored in the 2 dimensional relational formats at disc level.
ROLAP offers low latency, but it requires large storage space as well as slower processing and query response times.
In MOLAP, the structure of aggregation along with the data values are stored in multi dimensional format, takes more space with less time for data analysis compared to ROLAP.
MOLAP offers faster query response and processing times, but offers a high latency and requires average amount of storage space. This storage mode leads to duplication of data as the detail data is present in both the relational as well as the multidimensional storage.
In HOLAP, structure is stored in Relational model and data is stored in multi-dimensional model which provides optimal usage and space.
This storage mode offers optimal storage space, query response time, latency and fast processing times.
Default storage setting is MOLAP.
3. Types of Dimensions
|
Dimension
type
|
Description
|
|
Regular
|
A
dimension whose type has not been set to a special dimension type.
|
|
Time
|
A
dimension whose attributes represent time periods, such as years, semesters,
quarters, months, and days.
|
|
Organization
|
A
dimension whose attributes represent organizational information, such as employees
or subsidiaries.
|
|
Geography
|
A
dimension whose attributes represent geographic information, such as cities
or postal codes.
|
|
BillOfMaterials
|
A
dimension whose attributes represent inventory or manufacturing information,
such as parts lists for products.
|
|
Accounts
|
A
dimension whose attributes represent a chart of accounts for financial
reporting purposes.
|
|
Customers
|
A
dimension whose attributes represent customer or contact information.
|
|
Products
|
A
dimension whose attributes represent product information.
|
|
Scenario
|
A
dimension whose attributes represent planning or strategic analysis
information.
|
|
Quantitative
|
A
dimension whose attributes represent quantitative information.
|
|
Utility
|
A
dimension whose attributes represent miscellaneous information.
|
|
Currency
|
This
type of dimension contains currency data and metadata.
|
|
Rates
|
A
dimension whose attributes represent currency rate information.
|
|
Channel
|
A
dimension whose attributes represent channel information.
|
|
Promotion
|
A
dimension whose attributes represent marketing promotion information.
|
5. Types of Measures
Fully Additive Facts: These are facts which can be added across all the associated dimensions.
Fully Additive Facts: These are facts which can be added across all the associated dimensions.
For example, sales
amount is a fact which can be summed across different dimensions like customer,
geography, date, product, and so on.
Semi-Additive Facts: These are facts which can be added across only few dimensions rather than all dimensions.
For example, bank
balance is a fact which can be summed across the customer dimension (i.e. the
total balance of all the customers in a bank at the end of a particular
quarter). However, the same fact cannot be added across the date
dimension (i.e. the total balance at the end of quarter 1 is $X million and $Y
million at the end of quarter 2, so at the end of quarter 2, the total balance
is only $Y million and not $X+$Y).
Non-Additive Facts: These are facts which cannot be added across any of the dimensions in the cube. For example, profit margin is a fact which cannot be added across any of the dimensions.
For example, if
product P1 has a 10% profit and product P2 has a 10% profit then your net
profit is still 10% and not 20%. We cannot add profit margins across product
dimensions. Similarly, if your profit margin is 10% on Day1 and 10% on Day2,
then your net Profit Margin at the end of Day2 is still 10% and not 20%.
Derived Facts: Derived facts are the facts which are calculated from one or more base facts, often by applying additional criteria. Often these are not stored in the cube and are calculated on the fly at the time of accessing them. For example, profit margin.
Factless Facts: A factless fact table is one which only has references (Foreign Keys) to the dimensions and it does not contain any measures. These types of fact tables are often used to capture events (valid transactions without a net change in a measure value).
For example, a
balance enquiry at an ATM. Though there is no change in the account balance,
this transaction is still important for analysis purposes.
Textual Facts: Textual facts refer to the textual data present in the fact table, which is not measurable (non-additive), but is important for analysis purposes. For example, codes (i.e. product codes), flags (i.e. status flag), etc.
5. Types of relationships between dimensions and measure groups.
No relationship: The dimension and measure group are not related.
Regular: The dimension table is joined directly to the fact table.
Referenced: The dimension table is joined to an intermediate table, which in turn, is joined to the fact table.
Many to many: The dimension table is joined to an intermediate fact table, the intermediate fact table is joined, in turn, to an intermediate dimension table to which the fact table is joined.
Data mining: The target dimension is based on a mining model built from the source dimension. The source dimension must also be included in the cube.
Fact table: The dimension table is the fact table.
6. Proactive caching
Proactive caching can be configured to refresh the cache (MOLAP cache) either on a pre-defined schedule or in response to an event (change in the data) from the underlying relational database. Proactive caching settings also determine whether the data is queried from the underlying relational database (ROLAP) or is read from the outdated MOLAP cache, while the MOLAP cache is rebuilt.
Proactive caching helps in minimizing latency and achieve
high performance.
It enables a cube to reflect the most recent data present
in the underlying database by automatically refreshing the cube based on the
predefined settings.
Lazy aggregations:
When we reprocess SSAS cube then it actually bring
new/changed relational data into SSAS cube by reprocessing dimensions and measures.
Partition indexes and aggregations might be dropped due to changes in related
dimensions data so aggregations and partition indexes need to be reprocessed.
It might take more time to build aggregation and partition indexes.
If you want to bring cube online sooner without waiting
rebuilding of partition indexes and aggregations then lazy processing option
can be chosen. Lazy processing option bring SSAS cube online as soon as
dimensions and measures get processed. Partition indexes and aggregations are
triggered later as a background job.
Lazy processing option can be changed by server level property "OLAP\LazyProcessing\Enabled"
Advantage: Lazy processing
saves processing time as it brings as soon as measures and dimension data is
ready.
Disadvantage: User will see
performance hit when aggregation are getting build in background.
7. Partition processing options
Process Default: SSAS dynamically
chooses from one of the following process options.
Process Full: Drop all object stores, and rebuild the objects. This option is used when a structural change has been made to an object, for example, when an attribute hierarchy is added, deleted, or renamed.
Process Update: Forces a re-read of data and an update of dimension attributes. Flexible aggregations and indexes on related partitions will be dropped.
Process Add: For dimensions, adds new members and updates dimension attribute captions and descriptions.
Process Data: Processes data only without building aggregations or indexes. If there is data is in the partitions, it will be dropped before re-populating the partition with source data.
Process Index: Creates or rebuilds indexes and aggregations for all processed partitions. For unprocessed objects, this option generates an error.
Unprocess: Delete data from the object.
Process Structure: Drop the data and perform process default on all dimensions.
Process Clear: Drops the data in the object specified and any lower-level constituent objects. After the data is dropped, it is not reloaded.
Process Clear Structure: Removes all training data from a mining structure.
8. Difference between attribute hierarchy and user hierarchy
An Attribute Hierarchy is created by SSAS for every Attribute in a Dimension by default. An Attribute by default contains only 2 levels - An "All" level and a
"Detail" level which is nothing but the Dimension Members.
A User Defined Hierarchy is defined explicitly by the user/developer and often contains multiple levels. For example, a Calendar Hierarchy contains Year, Quarter, Month, and Date as its levels.
Some of the highlights/differences of Attribute and User Defined Hierarchies:
1. Attribute Hierarchies are always two-Level (Unless All Level is suppressed) whereas User Defined Hierarchies are often Multi-Level.
2. By default, Every Attribute in a Dimension has an Attribute Hierarchy whereas User Defined Hierarchies have to be explicitly defined by the user/developer.
3. Every Dimension has at least one Attribute Hierarchy by default whereas every Dimension does not necessarily contain a User Defined Hierarchy. In essence, a Dimension can contain zero, one, or more User Defined Hierarchies.
4. Attribute Hierarchies can be enabled or disabled. Disable the Attribute Hierarchy for those attributes which are commonly not used to slice and dice the data during analysis, like Address, Phone Number, and Unit Price etc. Doing this will improve the cube processing performance and also reduces the size of the cube as those attributes are not considered for performing aggregations.
5. Attribute Hierarchies can be made visible or hidden. When an Attribute Hierarchy is hidden, it will not be visible to the client application while browsing the Dimension/Cube. Attribute Hierarchies for those attributes which are part of the User Defined Hierarchies, like Day, Month, Quarter, and Year, which are part of the Calendar Hierarchy, can be hidden, since the attribute is available to the end users through the User Defined Hierarchy and helps eliminate the confusion/redundancy for end users.
Process Full: Drop all object stores, and rebuild the objects. This option is used when a structural change has been made to an object, for example, when an attribute hierarchy is added, deleted, or renamed.
Process Update: Forces a re-read of data and an update of dimension attributes. Flexible aggregations and indexes on related partitions will be dropped.
Process Add: For dimensions, adds new members and updates dimension attribute captions and descriptions.
Process Data: Processes data only without building aggregations or indexes. If there is data is in the partitions, it will be dropped before re-populating the partition with source data.
Process Index: Creates or rebuilds indexes and aggregations for all processed partitions. For unprocessed objects, this option generates an error.
Unprocess: Delete data from the object.
Process Structure: Drop the data and perform process default on all dimensions.
Process Clear: Drops the data in the object specified and any lower-level constituent objects. After the data is dropped, it is not reloaded.
Process Clear Structure: Removes all training data from a mining structure.
8. Difference between attribute hierarchy and user hierarchy
An Attribute Hierarchy is created by SSAS for every Attribute in a Dimension by default. An Attribute by default contains only 2 levels - An "All" level and a
"Detail" level which is nothing but the Dimension Members.
A User Defined Hierarchy is defined explicitly by the user/developer and often contains multiple levels. For example, a Calendar Hierarchy contains Year, Quarter, Month, and Date as its levels.
Some of the highlights/differences of Attribute and User Defined Hierarchies:
1. Attribute Hierarchies are always two-Level (Unless All Level is suppressed) whereas User Defined Hierarchies are often Multi-Level.
2. By default, Every Attribute in a Dimension has an Attribute Hierarchy whereas User Defined Hierarchies have to be explicitly defined by the user/developer.
3. Every Dimension has at least one Attribute Hierarchy by default whereas every Dimension does not necessarily contain a User Defined Hierarchy. In essence, a Dimension can contain zero, one, or more User Defined Hierarchies.
4. Attribute Hierarchies can be enabled or disabled. Disable the Attribute Hierarchy for those attributes which are commonly not used to slice and dice the data during analysis, like Address, Phone Number, and Unit Price etc. Doing this will improve the cube processing performance and also reduces the size of the cube as those attributes are not considered for performing aggregations.
5. Attribute Hierarchies can be made visible or hidden. When an Attribute Hierarchy is hidden, it will not be visible to the client application while browsing the Dimension/Cube. Attribute Hierarchies for those attributes which are part of the User Defined Hierarchies, like Day, Month, Quarter, and Year, which are part of the Calendar Hierarchy, can be hidden, since the attribute is available to the end users through the User Defined Hierarchy and helps eliminate the confusion/redundancy for end users.
9. Dimension, Hierarchy, Level, and Members
Dimensions in Analysis Services contain attributes that correspond to columns in dimension tables. These attributes appear as attribute hierarchies and can be organized into user-defined hierarchies, or can be defined as parent-child hierarchies based on columns in the underlying dimension table. Hierarchies are used to organize measures that are contained in a cube.
Hierarchy: is the relation between attributes in a dimension.
Level: refers to individual attribute within the Hierarchy.
10. Difference between database dimension and cube dimension
When you create a dimension using dimension wizard in BIDS, then you're creating a Database dimension in your AS database. Database dimensions is independent of cube and can be processed on their own.
When you build a cube, and you add dimensions to that
cube, you create cube dimensions: cube dimensions are instances of a database
dimension inside a cube.
A database dimension can be used in multiple cubes, and
multiple cube dimensions can be based on a single database dimension
The Database dimension has only Name and ID properties,
whereas a Cube dimension has several more properties.
Database dimension is created one where as Cube dimension
is referenced from database dimension.
Database dimension exists only once, whereas Cube
dimensions can be created more than one using ROLE PLAYING Dimensions concept.
11. Importance of CALCULATE keyword
in MDX script, data pass and limiting cube space
12. Effect of materialize
When setting up a dimension with a Reference relationship type, we have the option of "materializing" the dimension.
Select to store the attribute member in the intermediate dimension that links the attribute in the reference dimension to the fact table in the MOLAP
structure. This imporvies the qery performance, but increases the processing time and storage space.
If the option is not selected, only the relationship between the fact records and the intermediate dimension is stored in the cube. This means that Anaylysis services has to derive the aggregated values for the members of the referenced dimension when a query is executed, resulting in slower query performance.
13. Partition processing and Aggregation Usage Wizard
14. Perspectives, Translations, Linked Object Wizard
15. Handling late arriving dimensions / early arriving facts
16. Role playing Dimensions, Junk Dimensions, Conformed Dimensions, SCD and other types of dimensions
Role playing Dimension:
12. Effect of materialize
When setting up a dimension with a Reference relationship type, we have the option of "materializing" the dimension.
Select to store the attribute member in the intermediate dimension that links the attribute in the reference dimension to the fact table in the MOLAP
structure. This imporvies the qery performance, but increases the processing time and storage space.
If the option is not selected, only the relationship between the fact records and the intermediate dimension is stored in the cube. This means that Anaylysis services has to derive the aggregated values for the members of the referenced dimension when a query is executed, resulting in slower query performance.
13. Partition processing and Aggregation Usage Wizard
14. Perspectives, Translations, Linked Object Wizard
15. Handling late arriving dimensions / early arriving facts
16. Role playing Dimensions, Junk Dimensions, Conformed Dimensions, SCD and other types of dimensions
Role playing Dimension:
A Role-Playing Dimension is a Dimension which is connected
to the same Fact Table multiple times using different Foreign Keys.
eg: Consider a Time Dimension which is joined to the same Fact Table (Say FactSales) multiple times, each time using a different Foreign Key in the Fact Table like Order Date, Due Date, Ship Date, Delivery Date.
eg: Consider a Time Dimension which is joined to the same Fact Table (Say FactSales) multiple times, each time using a different Foreign Key in the Fact Table like Order Date, Due Date, Ship Date, Delivery Date.
Steps:
In Cube Designer, click the Dimension Usage tab.
Either click the 'Add Cube Dimension' button, or
right-click anywhere on the work surface and then click Add Cube Dimension.
In the Add Cube Dimension dialog box, select the dimension
that you want to add, and then click OK.
A Conformed Dimension is a
Dimension which connects to multiple Fact Tables across one or more Data Marts
(cubes). Conformed Dimensions are exactly the same structure, attributes,
values (dimension members), meaning and definition.
Example: A Date Dimension has exactly the same set of
attributes, same members and same meaning irrespective of which Fact Table it
is connected to.
A linked dimension is based on a
dimension that is stored in a separate Analysis Services Database which may or
may not be on the same server. You can create and maintain a dimension in just
one database and then reuse that dimension by creating linked dimensions for
use in multiple databases.
Linked Dimensions can be used when the exact same dimension can be used across multiple Cubes within an Organization like a Time Dimension, geography Dimension etc.
Here are some of the highlights of a Linked Dimension:
-More than one Linked Dimension can be created from a Single Database Dimension.
-These can be used to implement the concept of Conformed Dimensions.
-For an end user, a Linked Dimension appears like any other Dimension.
A Degenerate Dimension is a Dimension which is derived out of a Fact Table and it appears to the end user as a separate/distinct Dimension, its data is actually stored in the Fact Table. It's a Dimension table which does not have an underlying physical table of its own.
Degenerate Dimensions are commonly used when the Fact Table contains/represents Transactional data like Order Details, etc. and each Order has an Order Number associated with it, which forms the unique value in the Degenerate Dimension.
A Junk Dimension is often a collection of Unrelated Attributes like indicators, flags, codes, etc. It is also called as a Garbage Dimension.
Junk Dimensions are usually small in size.
One of the common scenarios is when a Fact Table contains a lot of Attributes which are like indicators, flags, etc. Using Junk Dimensions, such Attributes can be removed/cleaned up from a Fact Table.
SCD: The Slowly Changing Dimension (SCD) concept is basically about how the data modifications are absorbed and maintained in a Dimension Table.
The new (modified) record and the old record(s) are identified using some kind of a flag like say IsActive, IsDeleted etc. or using Start and End Date fields to indicate the validity of the record.
17. Parent Child Hierarchy, NamingTemplate property, MemberWithLeafLevelData property
Linked Dimensions can be used when the exact same dimension can be used across multiple Cubes within an Organization like a Time Dimension, geography Dimension etc.
Here are some of the highlights of a Linked Dimension:
-More than one Linked Dimension can be created from a Single Database Dimension.
-These can be used to implement the concept of Conformed Dimensions.
-For an end user, a Linked Dimension appears like any other Dimension.
A Degenerate Dimension is a Dimension which is derived out of a Fact Table and it appears to the end user as a separate/distinct Dimension, its data is actually stored in the Fact Table. It's a Dimension table which does not have an underlying physical table of its own.
Degenerate Dimensions are commonly used when the Fact Table contains/represents Transactional data like Order Details, etc. and each Order has an Order Number associated with it, which forms the unique value in the Degenerate Dimension.
A Junk Dimension is often a collection of Unrelated Attributes like indicators, flags, codes, etc. It is also called as a Garbage Dimension.
Junk Dimensions are usually small in size.
One of the common scenarios is when a Fact Table contains a lot of Attributes which are like indicators, flags, etc. Using Junk Dimensions, such Attributes can be removed/cleaned up from a Fact Table.
SCD: The Slowly Changing Dimension (SCD) concept is basically about how the data modifications are absorbed and maintained in a Dimension Table.
The new (modified) record and the old record(s) are identified using some kind of a flag like say IsActive, IsDeleted etc. or using Start and End Date fields to indicate the validity of the record.
17. Parent Child Hierarchy, NamingTemplate property, MemberWithLeafLevelData property
18. How will you keep measure in cube without showing it to user?
19. How to pass parameter in MDX
Here is an example, suppose this is your query:
select {[Measures].[Internet Order Quantity]} on 0,
[Product].[Category].[Category] on 1
from [Adventure Works]
where [Date].[Calendar Year].&[2002]
You can modify it like this:
select {[Measures].[Internet Order Quantity]} on 0,
[Product].[Category].[Category] on 1
from [Adventure Works]
where strtomember(@P1)
Now, if you pass the value [Date].[Calendar Year].&[2002] to the P1, then it will run just like:
where [Date].[Calendar Year].&[2002]
STRTOSET returns a set.
STRTOMEMBER returns a member.
20. SSAS 2008 vs SSAS 2012
21. Dimension security vs Cell security
22. SCOPE statement, THIS keyword, SUBCUBE
23. CASE (CASE, WHEN, THEN, ELSE, END) statement, IF THEN END IF, IS keyword, HAVING clause
24. CELL CALCULATION and CONDITION clause
25. RECURSION and FREEZE statement
26. Common types of errors encountered while processing a dimension / measure groups / cube
27. Logging and monitoring MDX scripts and cube performance
28. What do you understand by
attribute relationship? what are the main advantages in using attribute
relationship?
An Attribute Relationship is a relationship between
various attributes within a Dimension. By default, every Attribute in a
Dimension is related to the Key
Attribute.
There are basically 2 types of Attribute Relationships: Rigid, Flexible
29. What is natural hierarchy and how will you create it?
Attribute.
There are basically 2 types of Attribute Relationships: Rigid, Flexible
29. What is natural hierarchy and how will you create it?
Natural hierarchies, where each attribute is related
either directly or indirectly to all other attributes in the same hierarchy, as
in product category - product
subcategory - product name
30. What do you understand by rigid
and flexible relationship? Which one is better from performance perspective?
Rigid: Attribute
Relationship should be set to Rigid when the relationship between those
attributes is not going to change over time. For example,
relationship between a Month and a Date is Rigid since a
particular Date always belongs to a particular Month like 1st Feb 2012 always
belongs to Feb
Month of 2012. Try to set the relationship to Rigid
wherever possible.
Flexible: Attribute
Relationship should be set to Flexible when the relationship between those
attributes is going to change over time. For example, relationship between an
Employee and a Manager is Flexible since a particular Employee might work under
one manager during this year (time period) and under a different manager during
next year (another time period).
31. In which scenario, you would like
to go for materializing dimension?
Reference dimensions let you create a relationship between
a measure group and a dimension using an intermediate dimension to act as a
bridge between
them.
32. In dimension usage tab, how many types of
joins are possible to form relationship between measure group and dimension?
33. What is deploy, process and
build?
Bulid: Verifies the project files and create several local
files.
Deploy: Deploy the structure of the cube(Skeleton) to the server.
Process: Read the data from the source and build the dimesions and cube structures
Deploy: Deploy the structure of the cube(Skeleton) to the server.
Process: Read the data from the source and build the dimesions and cube structures
34. Can you create server time
dimension in analysis services(Server time dimension)?
35. How many types of dimension are
possible in SSAS?
Account
Bill of Materials
Currency
Channel
Customer
Geography
Organizations
Products
promotion
Regular
Scenario
Time
Unary
Bill of Materials
Currency
Channel
Customer
Geography
Organizations
Products
promotion
Regular
Scenario
Time
Unary
36. What is time intelligence? How
will you implement in SSAS?
37. What do you understand by linked
cube or linked object feature in SSAS?
38. How will you write back to
dimension using excel or any other client tool?
39. What do you understand by dynamic
named set (SSAS 2008)? How is i different from static named set?
40. In Process Update, which
relationship will be better(Rigid and Flexible relationship)?
41. What is the difference between
"ProcessingGroup" ByAttribute and ByTable?
42. What do you understand by
following properties of dimension attribute.
Default Member
AttributeHierarchyEnabled
AttributeHierarchyOptimizedState
DiscretizationMethod
OrderBy
OrderByAttribute
AttributeHierarchyEnabled
AttributeHierarchyOptimizedState
DiscretizationMethod
OrderBy
OrderByAttribute
43. What are different storage
mode option in SQL server analysis services and which scenario, they will be
useful?
44. How will you implement data
security for given scenario in analysis service data?
"I have 4 cubes and 20
dimension. I need to give access to CEO, Operation managers and Sales managers
and employee.
1) CEO can see all the data of all 4
cubes.
2) Operation Managers can see only
data related to their cube. There are four operation managers.
3) Employees can see only certain
dimension and measure groups data. (200 Employees) "
45. What are the options to deploy
SSAS cube in production?
Right click on Project in Solution Explorer ->
Properties
Build -> Select ' Output Path'
Deployment ->
Processing Option - Default, Full, Do Not Process
Transactional Deployment - False, True
Deployment Mode - Deploy All, Deploy Changes only
1.BIDS
In BIDS from the build menu – select the build option (or right click on the project in the solution explorer).
The build process will create four xml files in the bin subfolder of the project folder
.asdatabase - is the main object definition file
.configsettings
.deploymentoptions
.deploymenttargets
Build -> Select ' Output Path'
Deployment ->
Processing Option - Default, Full, Do Not Process
Transactional Deployment - False, True
Deployment Mode - Deploy All, Deploy Changes only
1.BIDS
In BIDS from the build menu – select the build option (or right click on the project in the solution explorer).
The build process will create four xml files in the bin subfolder of the project folder
.asdatabase - is the main object definition file
.configsettings
.deploymentoptions
.deploymenttargets
2. Deploy
Deployment via BIDS will overwrite the destination database management settings – so is not recommended for production deployment.
A more controllable option is the Deployment wizard, available in interactive or command line mode.
Run the wizard from Start -> All Programs ->Microsoft Sql Server -> Analysis Services -> deployment wizard
1. Browse to the .asdatabase file created by the build
2. connect to the target server
3. Configure how partitions and roles should be deployed
4. specify how configuration settings are deployed
5. Specify Processing options:
Default processing allows SSAS to decide what needs to be done; Full processing can be used to process all objects. You can also choose not to process at all.
6. choose whether to deploy instantly or to create an XMLA command script for later deployment. The script will be created in the same location as the
Deployment via BIDS will overwrite the destination database management settings – so is not recommended for production deployment.
A more controllable option is the Deployment wizard, available in interactive or command line mode.
Run the wizard from Start -> All Programs ->Microsoft Sql Server -> Analysis Services -> deployment wizard
1. Browse to the .asdatabase file created by the build
2. connect to the target server
3. Configure how partitions and roles should be deployed
4. specify how configuration settings are deployed
5. Specify Processing options:
Default processing allows SSAS to decide what needs to be done; Full processing can be used to process all objects. You can also choose not to process at all.
6. choose whether to deploy instantly or to create an XMLA command script for later deployment. The script will be created in the same location as the
.asdatabase file.
46. What are the options available to
incrementally load relational data into SSAS cube?
Use Slowly Changing Dimesnion
47. Why will you use aggregation at
remote server?
48. What are different ways to
create aggregations in SSAS?
49. What do you understand by Usage
based optimization?
50. Can we use different
aggregation scheme for different partitions?
51. Why will you use perspective in
SSAS?
52. What are KPIs? How will you
create KPIs in SSAS?
53. What are the main feature
differences in SSAS 2005 and SSAS 2008 from developer point of view?
54.What are the aggregate functions
available for measure in SSAS?
Sum, Min, Max, Count, and Distinct Count
55. What are the processing modes
available for measure group? What do you understand by lazy aggregation?
56. How can you improve dimension
design?
1: Limit the Number of Dimensions Per Measure Group and
Number of Attributes Per Dimension.
AttributeHierarchyOptimizedState: Determines the level of optimization applied to the attribute hierarchy. By default, an attribute hierarchy is FullyOptimized, which means that Analysis Services builds indexes for the attribute hierarchy to improve query performance. The other option, NotOptimized, means that no indexes are built for the attribute hierarchy.
2: Use Dimension Properties Effectively
For large dimensions that expose millions of rows and have a large number of attributes, pay particular attention to the ProcessingGroup property. By
default, this property is assigned a value of ByAttribute.
3: Use Regular Dimension Relationship Whenever Possible
4: Use Integer Data Type for Attribute Keys If at All Possible
5: Use Natural Hierarchies When Possible
AttributeHierarchyOptimizedState: Determines the level of optimization applied to the attribute hierarchy. By default, an attribute hierarchy is FullyOptimized, which means that Analysis Services builds indexes for the attribute hierarchy to improve query performance. The other option, NotOptimized, means that no indexes are built for the attribute hierarchy.
2: Use Dimension Properties Effectively
For large dimensions that expose millions of rows and have a large number of attributes, pay particular attention to the ProcessingGroup property. By
default, this property is assigned a value of ByAttribute.
3: Use Regular Dimension Relationship Whenever Possible
4: Use Integer Data Type for Attribute Keys If at All Possible
5: Use Natural Hierarchies When Possible
57. What are the performance issues
with parent child hierarchy?
In parent-child hierarchies, aggregations are created only
for the key attribute and the top attribute, i.e., the All attribute unless it
is disabled.
58. What do you understand by formula
engine and storage engine?
Formula Engine is single-threaded, Storage Engine (SE) is
multi-threaded.
The Query Processor Cache/Formula Engine Cache caches the calculation results whereas the Storage Engine Cache caches aggregated/fact data being
The Query Processor Cache/Formula Engine Cache caches the calculation results whereas the Storage Engine Cache caches aggregated/fact data being
queried.
59. How can you improve overall cube
performance?
1. Partitioning the cube can help to reduce the processing time.
The benefit of partitioning is that it allows to process multiple
partitions in parallel on a
server that has multiple processors.
2. Keep Cube space as small as possible by only including measures groups that are needed.
3. Place the measures that are queried together in same measure group. A query that retrieves measures from multiple measure groups requires multiple storage space.
4. Define the aggregations to reduce the number of records that the storage engine needs to scan from disk to satisfy a query.
5. Avoid designing excessive aggregations. Excessive aggregations may reduce processing performance and query performance.
Regarding the best possible processing strategy, the following steps:
1. Process Update all the dimensions that could have had data changed. Depending on the nature of the changes in the dimension table, Process Update can affect dependent partitions. If only new members were added, then the partitions are not affected. But if members were deleted or if member relationships changed, then some of the aggregation data and bitmap indexes on the partitions are dropped.
2. Process Data the partitions that have changed data (which are usually the most recent partitions). Of course, the smaller the partition, the better, so try to use daily partitions instead of monthly or use monthly partitions instead of yearly.
3. Process Index for the rest of the partitions
server that has multiple processors.
2. Keep Cube space as small as possible by only including measures groups that are needed.
3. Place the measures that are queried together in same measure group. A query that retrieves measures from multiple measure groups requires multiple storage space.
4. Define the aggregations to reduce the number of records that the storage engine needs to scan from disk to satisfy a query.
5. Avoid designing excessive aggregations. Excessive aggregations may reduce processing performance and query performance.
Regarding the best possible processing strategy, the following steps:
1. Process Update all the dimensions that could have had data changed. Depending on the nature of the changes in the dimension table, Process Update can affect dependent partitions. If only new members were added, then the partitions are not affected. But if members were deleted or if member relationships changed, then some of the aggregation data and bitmap indexes on the partitions are dropped.
2. Process Data the partitions that have changed data (which are usually the most recent partitions). Of course, the smaller the partition, the better, so try to use daily partitions instead of monthly or use monthly partitions instead of yearly.
3. Process Index for the rest of the partitions
MDX
1. Explain the structure of MDX
query?
2. MDX functions?
MDX KPI Functions:
KPICurrentTimeMember, KPIGoal, KPIStatus, KPITrend
KPIValue, KPIWeight
MDX Metadata Functions:
Axis, Count (Dimension), Count (Hierarchy Levels), Count (Tuple)
Hierarchy, Level, Levels, Name,Ordinal, UniqueName
MDX Navigation Functions:
Ancestor, Ancestors, Ascendants, Children
Cousin, Current, CurrentMember, CurrentOrdinal
DataMember, DefaultMember, FirstChild, FirstSibling
IsAncestor, IsGeneration, IsLeaf, IsSibling
Lag, LastChild, LastSibling, Lead
LinkMember, LookupCube, NextMember, Parent
PrevMember, Properties, Siblings, UnknownMember
MDX Other Functions:
CalculationCurrentPass, CalculationPassValue, CustomData, Dimension
Dimensions, Error, Item (Member), Item (Set)
Members (String), Predict, SetToArray
MDX Set Functions:
AddCalculatedMembers, AllMembers, BottomCount, BottomPercent
BottomSum, Crossjoin, Descendants, Distinct
Except, Exists, Extract, Filter
Generate, Head, Hierarchize, Intersect
MeasureGroupMeasures, Members (Set), NonEmpty, NonEmptyCrossjoin
Order, StripCalculatedMembers, Subset, Tail
TopCount, TopPercent, TopSum, Union
Unorder
MDX Statistical Functions:
Aggregate, Avg, CoalesceEmpty, Correlation
Count (Set), Covariance, CovarianceN, DistinctCount
LinRegIntercept, LinRegPoint, LinRegR2, LinRegSlope
LinRegVariance, Max, Median, Min
Rank, RollupChildren, Stdev, StdevP
Sum, Var, VarP, VisualTotals
MDX String Functions:
MemberToStr, NameToSet, Root, SetToStr
StrToMember, StrToSet, StrToTuple, StrToValue,TupleToStr, UserName
MDX SubCube Functions:
Leaves, This
MDX Time Functions:
ClosingPeriod, LastPeriods, Mtd, OpeningPeriod
ParallelPeriod, PeriodsToDate, Qtd, Wtd,Ytd
MDX UI Functions:
DrilldownLevel, DrilldownLevelBottom, DrilldownLevelTop, DrilldownMember
DrilldownMemberBottom, DrilldownMemberTop, DrillupLevel, DrillupMember
ToggleDrillState
MDX Value Functions:
IIf, IsEmpty, MemberValue, ValidMeasure, Value
3. What is the difference between set and tuple?
Tuple: It is a collection of members from different Dimension
Set: collection of one or More tuples from same dimension
4. What do you understand by Named set?
Named sets are simply MDX expression that return a set of members.
To define a named set:
CREATE SET MySet AS SomeSetExpression
or you can use
WITH SET MySet AS SomeSetExpression
The different between the two is the scope. Using WITH specifies the scope of the named set as the query, so as soon as the query finishes executing, that named set is gone. Using CREATE, the scope of the query is limited to the MDX session as long as you don't drop the set.
When defining your named set, you also have the option to specify when the named set is evaluated using DYNAMIC or STATIC, as seen here:
CREATE DYNAMIC SET MySet AS SomeSetExpression
or
CREATE STATIC SET MySet AS SomeSetExpression
A Dynamic Named Set respects the context of a query's subcube and the query's WHERE clause and is evaluated at the time the query is executed.
A Static Named Set is evaluated at the time the cube is processed and will not respect any subcube context and slicers in WHERE clause.
Example 1:
CREATE SET DateRange AS
[Date].[Calendar Year].&[2001] : [Date].[Calendar Year].&[2004]
SELECT [Measures].[Reseller Sales Amount] ON COLUMNS,
DateRange ON ROWS
FROM [Adventure Works]
Example 2:
WITH SET SouthEastUS AS
{[Geography].[State-Province].&[AL]&[US],
[Geography].[State-Province].&[FL]&[US],
[Geography].[State-Province].&[GA]&[US],
[Geography].[State-Province].&[SC]&[US]}
SELECT [Measures].[Reseller Sales Amount] ON COLUMNS,
SouthEastUS ON ROWS
FROM [Adventure Works]
5. How will you differentiate among level, member, attribute, hierarchy?
6. What are the differences among exists, existing and scope?
7. What will happen if we remove CALCULATE keyword in the script?
8. How will you pass parameter in MDX?
9. What is the difference between .MEMBERS and .CHILDREN?
10.What is the difference between NON EMPTY keyword and NONEMPTY() function?
NON EMPTY:
Non Empty is prefixed before the sets defining the axes and is used for removing NULLs.
In short, only the rows having NULL for all the members of the set defined in the column axis is filtered out. This is because the Non Empty operator works on the top level of the query. Internally, the sets defined for the axes are generated first and then the tuples having NULL values are removed.
SELECT
NON EMPTY
{
[Measures].[Hits]
,[Measures].[Subscribers]
,[Measures].[Spam]
} ON COLUMNS
,{
[Geography].[Country].Children
} ON ROWS
FROM [Blog Statistics];
NONEMPTY():
The NonEmpty() returns the set of tuples that are not empty from a specified set, based on the cross product of the specified set with a second set. Suppose we want to see all the measures related to countries which have a non-null value for Subscribers
SELECT
{
[Measures].[Hits]
,[Measures].[Subscribers]
,[Measures].[Spam]
} ON COLUMNS
,{
NonEmpty
(
[Geography].[Country].Children
,[Measures].[Subscribers]
)
} ON ROWS
FROM [Blog Statistics];
11. Functions used commonly in MDX like Filter, Descendants, BAsc and others
12. Difference between NON EMPTY keyword and function, NON_EMPTY_BEHAVIOR, ParallelPeriod, AUTOEXISTS
13. Difference between static and dynamic set
CREATE DYNAMIC SET MySet AS SomeSetExpression
or
CREATE STATIC SET MySet AS SomeSetExpression
A respects the context of a query's subcube and the query's WHERE clause and is evaluated at the time the query is executed.
A Static Named Set is evaluated at the time the cube is processed and will not respect any subcube context and slicers in WHERE clause.
14. Difference between natural and unnatural hierarchy, attribute relationships
15. Difference between rigid and flexible relationships
16. Write MDX for retrieving top 3 customers based on internet sales amount?
17. Write MDX to find current month's start and end date?
18. Write MDX to compare current month's revenue with last year same month revenue?
19. Write MDX to find MTD(month to date), QTD(quarter to date) and YTD(year to date) internet sales amount for top 5 products?
20. Write MDX to find count of regions for each country?
21. Write MDX to rank all the product category based on calendar year 2005 internet sales amount?
22. Write MDX to extract nth position tuple from specific set?
syntax:
Index syntax:
Set_Expression.Item(Index)
String expression syntax:
Set_Expression.Item(String_Expression1 [ ,String_Expression2,...n])
The following example returns ([1996],Sales):
{([1996],Sales), ([1997],Sales), ([1998],Sales)}.Item(0)
23. Write MDX to set default member for particular dimension?
24. What are the performance consideration for improving MDX queries?
25. Is Rank MDX function performance intensive?
26. Which one is better from performance point of view...NON Empty keyword or NONEMPTY function?
27. How will you find performance bottleneck in any given MDX?
28. What do you understand by storage engine and formula engine?
2. MDX functions?
MDX KPI Functions:
KPICurrentTimeMember, KPIGoal, KPIStatus, KPITrend
KPIValue, KPIWeight
MDX Metadata Functions:
Axis, Count (Dimension), Count (Hierarchy Levels), Count (Tuple)
Hierarchy, Level, Levels, Name,Ordinal, UniqueName
MDX Navigation Functions:
Ancestor, Ancestors, Ascendants, Children
Cousin, Current, CurrentMember, CurrentOrdinal
DataMember, DefaultMember, FirstChild, FirstSibling
IsAncestor, IsGeneration, IsLeaf, IsSibling
Lag, LastChild, LastSibling, Lead
LinkMember, LookupCube, NextMember, Parent
PrevMember, Properties, Siblings, UnknownMember
MDX Other Functions:
CalculationCurrentPass, CalculationPassValue, CustomData, Dimension
Dimensions, Error, Item (Member), Item (Set)
Members (String), Predict, SetToArray
MDX Set Functions:
AddCalculatedMembers, AllMembers, BottomCount, BottomPercent
BottomSum, Crossjoin, Descendants, Distinct
Except, Exists, Extract, Filter
Generate, Head, Hierarchize, Intersect
MeasureGroupMeasures, Members (Set), NonEmpty, NonEmptyCrossjoin
Order, StripCalculatedMembers, Subset, Tail
TopCount, TopPercent, TopSum, Union
Unorder
MDX Statistical Functions:
Aggregate, Avg, CoalesceEmpty, Correlation
Count (Set), Covariance, CovarianceN, DistinctCount
LinRegIntercept, LinRegPoint, LinRegR2, LinRegSlope
LinRegVariance, Max, Median, Min
Rank, RollupChildren, Stdev, StdevP
Sum, Var, VarP, VisualTotals
MDX String Functions:
MemberToStr, NameToSet, Root, SetToStr
StrToMember, StrToSet, StrToTuple, StrToValue,TupleToStr, UserName
MDX SubCube Functions:
Leaves, This
MDX Time Functions:
ClosingPeriod, LastPeriods, Mtd, OpeningPeriod
ParallelPeriod, PeriodsToDate, Qtd, Wtd,Ytd
MDX UI Functions:
DrilldownLevel, DrilldownLevelBottom, DrilldownLevelTop, DrilldownMember
DrilldownMemberBottom, DrilldownMemberTop, DrillupLevel, DrillupMember
ToggleDrillState
MDX Value Functions:
IIf, IsEmpty, MemberValue, ValidMeasure, Value
3. What is the difference between set and tuple?
Tuple: It is a collection of members from different Dimension
Set: collection of one or More tuples from same dimension
4. What do you understand by Named set?
Named sets are simply MDX expression that return a set of members.
To define a named set:
CREATE SET MySet AS SomeSetExpression
or you can use
WITH SET MySet AS SomeSetExpression
The different between the two is the scope. Using WITH specifies the scope of the named set as the query, so as soon as the query finishes executing, that named set is gone. Using CREATE, the scope of the query is limited to the MDX session as long as you don't drop the set.
When defining your named set, you also have the option to specify when the named set is evaluated using DYNAMIC or STATIC, as seen here:
CREATE DYNAMIC SET MySet AS SomeSetExpression
or
CREATE STATIC SET MySet AS SomeSetExpression
A Dynamic Named Set respects the context of a query's subcube and the query's WHERE clause and is evaluated at the time the query is executed.
A Static Named Set is evaluated at the time the cube is processed and will not respect any subcube context and slicers in WHERE clause.
Example 1:
CREATE SET DateRange AS
[Date].[Calendar Year].&[2001] : [Date].[Calendar Year].&[2004]
SELECT [Measures].[Reseller Sales Amount] ON COLUMNS,
DateRange ON ROWS
FROM [Adventure Works]
Example 2:
WITH SET SouthEastUS AS
{[Geography].[State-Province].&[AL]&[US],
[Geography].[State-Province].&[FL]&[US],
[Geography].[State-Province].&[GA]&[US],
[Geography].[State-Province].&[SC]&[US]}
SELECT [Measures].[Reseller Sales Amount] ON COLUMNS,
SouthEastUS ON ROWS
FROM [Adventure Works]
5. How will you differentiate among level, member, attribute, hierarchy?
6. What are the differences among exists, existing and scope?
7. What will happen if we remove CALCULATE keyword in the script?
8. How will you pass parameter in MDX?
9. What is the difference between .MEMBERS and .CHILDREN?
10.What is the difference between NON EMPTY keyword and NONEMPTY() function?
NON EMPTY:
Non Empty is prefixed before the sets defining the axes and is used for removing NULLs.
In short, only the rows having NULL for all the members of the set defined in the column axis is filtered out. This is because the Non Empty operator works on the top level of the query. Internally, the sets defined for the axes are generated first and then the tuples having NULL values are removed.
SELECT
NON EMPTY
{
[Measures].[Hits]
,[Measures].[Subscribers]
,[Measures].[Spam]
} ON COLUMNS
,{
[Geography].[Country].Children
} ON ROWS
FROM [Blog Statistics];
NONEMPTY():
The NonEmpty() returns the set of tuples that are not empty from a specified set, based on the cross product of the specified set with a second set. Suppose we want to see all the measures related to countries which have a non-null value for Subscribers
SELECT
{
[Measures].[Hits]
,[Measures].[Subscribers]
,[Measures].[Spam]
} ON COLUMNS
,{
NonEmpty
(
[Geography].[Country].Children
,[Measures].[Subscribers]
)
} ON ROWS
FROM [Blog Statistics];
11. Functions used commonly in MDX like Filter, Descendants, BAsc and others
12. Difference between NON EMPTY keyword and function, NON_EMPTY_BEHAVIOR, ParallelPeriod, AUTOEXISTS
13. Difference between static and dynamic set
CREATE DYNAMIC SET MySet AS SomeSetExpression
or
CREATE STATIC SET MySet AS SomeSetExpression
A respects the context of a query's subcube and the query's WHERE clause and is evaluated at the time the query is executed.
A Static Named Set is evaluated at the time the cube is processed and will not respect any subcube context and slicers in WHERE clause.
14. Difference between natural and unnatural hierarchy, attribute relationships
15. Difference between rigid and flexible relationships
16. Write MDX for retrieving top 3 customers based on internet sales amount?
17. Write MDX to find current month's start and end date?
18. Write MDX to compare current month's revenue with last year same month revenue?
19. Write MDX to find MTD(month to date), QTD(quarter to date) and YTD(year to date) internet sales amount for top 5 products?
20. Write MDX to find count of regions for each country?
21. Write MDX to rank all the product category based on calendar year 2005 internet sales amount?
22. Write MDX to extract nth position tuple from specific set?
syntax:
Index syntax:
Set_Expression.Item(Index)
String expression syntax:
Set_Expression.Item(String_Expression1 [ ,String_Expression2,...n])
The following example returns ([1996],Sales):
{([1996],Sales), ([1997],Sales), ([1998],Sales)}.Item(0)
23. Write MDX to set default member for particular dimension?
24. What are the performance consideration for improving MDX queries?
25. Is Rank MDX function performance intensive?
26. Which one is better from performance point of view...NON Empty keyword or NONEMPTY function?
27. How will you find performance bottleneck in any given MDX?
28. What do you understand by storage engine and formula engine?
