BI Interview Questions & Answers Part 1:
Q) How can I compare data in R/3 with data in a BW Cube after the daily delta loads? Are there any standard procedures for checking them or matching the number of records?
A) Go to R/3 TC RSA3 and run the extractor. It will give you the number of records extracted. Then go to BW Monitor to check the number of records in the PSA and check to see if it is the same.
RSA3 is a simple extractor checker program that allows you to rule out extract problems in R/3. It is simple to use, but only really tells you if the extractor works. Since records that get updated into Cubes/ODS structures are controlled by Update Rules, you will not be able to determine what is in the Cube compared to what is in the R/3 environment. You will need to compare records on a 1:1 basis against records in R/3 transactions for the functional area in question. I would recommend enlisting the help of the end user community to assist since they presumably know the data.
To use RSA3, go to it and enter the extractor ex: 2LIS_02_HDR. Click executes and you will see the record count, you can also go to display that data. You are not modifying anything so what you do in RSA3 has no effect on data quality afterwards. However, it will not tell you how many records should be expected in BW for a given load. You have that information in the monitor RSMO during and after data loads. From RSMO for a given load you can determine how many records were passed through the transfer rules from R/3, how many targets were updated, and how many records passed through the Update Rules. It also gives you error messages from the PSA.
Q) How can I copy queries from an info cube to another info cube in Business Explorer?
A) By using the Transaction RSZC in our BW system.
Q) What is the feature of Delta queue?
A) It collects the data from R/3 and store it within the delta queue in R/3 until next delta extract. The DataSource reads the Delta Queue data and push it to BW.
How do we see the data that’s collected and stored in the delta queue?
Go to Transaction RSA7 on R/3 to view the contents of the delta queue. Note only extractors that have been successfully initialized will show up in this queue
Q) what is the difference between V1, V2 and V3 updates?
A) >> V1 Update: It is a Synchronous update. Here the Statistics update is carried out at the same time as the document update (in the application tables).
>> V2 Update: It is an Asynchronous update. Statistics update and the Document update take place as different tasks.
V1 & V2 don’t need scheduling.
>> Serialized V3 Update: The V3 collective update must be scheduled as a job (via LBWE). Here, document data is collected in the order it was created and transferred into the BW as a batch job. The transfer sequence may not be the same as the order in which the data was created in all scenarios. V3 update only processes the update data that is successfully processed with the V2 update.
Q) What is compression?
It is a process used to delete the Request IDs and this saves space
Q) what is Rollup?
This is used to load new DataPackages (requests) into the InfoCube aggregates. If we have not performed a rollup then the new InfoCube data will not be available while reporting on the aggregate.
Q) What is the transaction for the Administrator work bench?
A) Transaction RSA 1
Q) The BEx Web Analyzer:
A) The BEx Web Analyzer is a standalone, convenient Web application for data analysis that you can call using a URL or as an iView in the portal.
The Web Analyzer allows you to execute ad hoc analyses on the Web: When you have selected a data provider
(query, query view, InfoProvider, external data source), the data is displayed in a table with a navigation pane.
You can navigate to the data and use other Web Analyzer functions available in the application toolbar. For
example, you can change the type of data display, use the information broadcasting functions to broadcast
your analyses to others, and create printable versions of your analyses.
In the Web Analyzer, you can save the data view generated from navigation and analysis as a query view by
choosing Save View in the context menu, and you can save the ad hoc analysis by choosing Save As. When
the query view is saved, only the data view is saved; when the ad hoc analysis is saved, the entire Web
application is saved, including the properties of Web items and the layout of the data.
Q) Where can you implement currency translations?
A) Query definition or Query Run Time or Transformation Rules.
Q) What must be in place before you are able to define ‘Exception Cells’ in the query definition?
A) Structures, one in rows and one in columns, when you define selection criteria and formulas for structural components and there are two structural components of a query, generic cell definitions are created at the intersection of the structural components that determine the values to be presented in the cell.
Cell-specific definitions allow you to define explicit formulas and selection conditions for cells as well as implicit cell definitions. This means that you can override implicitly created cell values. This function allows you to design much more detailed queries.
You can define exception cells only for queries that have two structures. For example, you can use
characteristic values in one structure and key figures in the other. You can then define cells if these
prerequisites have been met.
A cell is the intersection between two structural components. The term cell for the function Defining Exception Cells should not be confused with the term cell in Microsoft Excel. The formulas or selection conditions that you define for a cell always take effect at the intersection between two structural components. If a drilldown characteristic has two different characteristic values, the cell definition always takes effect at the intersection between the characteristic value and the key figure.
Q) About Attributes.
A) 1. Attributes are stored against Characteristic in BI.
2. There are two types of Attributes Text and Navigation
3. Navigation Attributes provide functionality similar to characteristic in query definition.
Attributes are part of Master Data and not Meta Data.
Characteristic attributes can be converted into navigation attributes. They can be selected in the query in exactly the same way as the characteristics for an InfoCube. In this case, a new edge/dimension is added to the InfoCube. During the data selection for the query, the data manager connects the InfoProvider and the master data table (‘join’) in order to fill the Query.
e.g. If you need the costs of the cost center drilled down by person responsible:
You use the attribute ‘Cost Center Manager’ for the characteristic ‘Cost Center’. If you want to navigate in the query using the cost center manager, you have to create the attribute ‘Cost Center Manager’ as a navigation attribute, and flag it as a navigation characteristic in the InfoProvider.
When executing the query there is no difference between navigation attributes and the characteristics for an InfoCube. All navigation functions in the OLAP processor are also possible for navigation attributes.
Q. What is the definition of a restricted key Figure?
A) Basic key figure of the Infoprovider that has been restricted by one or more characteristic selections.
You can restrict the key figures of an InfoProvider for reuse by selecting one or more characteristics. The key figures that are restricted by one or more characteristic selections can be basic key figures, calculated key figures, or key figures that are already restricted.
Q) Use of Calculated Key Figures?
A) 1. Calculated Key Figures can be stored at Infoprovider level.
2. Calculated Key Figures can be stored at Query level
In the Query Designer, you use formulas to recalculate the key figures in an InfoProvider so that you can reuse them. Calculated key figures consist of formula definitions containing basic key figures, restricted key figures or pre-calculated key figures.
If you define a calculated key figure at the InfoProvider level, you can use this calculated key figure in all queries based on this InfoProvider by moving the key figure into the rows or columns of the query using drag and drop.
If you define a Calculated Key Figure at the Query level, it is valid only for the Query in question and cannot be resued.
Q) Your company wants to consolidate Cost Center data from an SAP system and an external system via a file interface. In the legacy system, the cost Center number is 13 characters long but the SAP system only allows 10 characters. Which one of the following approaches would you use recommend.
A) Change the delivered content object 0COSTCENTER.
Unlike other SAP products, versioning allows both a customer version and SAP version of the same object, and they can be different.
This approach leads to faster implementations and is generally taken in ‘real life’ projects.
Q) Why do we need to normalize a data model?
A) Data normalization is a process in which data attributes within a data model are organized to increase the cohesion of entity types. In other words, the goal of data normalization is to reduce and even eliminate data redundancy, The advantage of having a highly normalized data schema is that information is stored in one place and one place only, reducing the possibility of inconsistent data.
Please note that in the extended star schema only the Fact Table (and not dimension table) is normalized.
Q) Aggregates can be created for which of the following?
A) Aggregates can be created only for InfoCubes. You can create multiple aggregates against the same infocube.
Q) Aggregates can be automatically proposed by the BI system. Which of the following options are available?
A) Propose from Query and Propose from BI Statistics.
You can choose Proposals in the menu if you want the system to propose aggregates. You have the following options:
● Proposals from queries: The system considers the queries that are created for an InfoCube.
● Proposals from the previous navigation: The system evaluates the last navigational step that you carried out with a query.
● Proposals from BI Statistics (tables): The system considers BI statistical data (database tables).
● Proposals from BI Statistics (InfoCube): The system considers the data that is contained in the BI Statistics InfoCube.
Q) How can I compare data in R/3 with data in a BW Cube after the daily delta loads? Are there any standard procedures for checking them or matching the number of records?
A) Go to R/3 TC RSA3 and run the extractor. It will give you the number of records extracted. Then go to BW Monitor to check the number of records in the PSA and check to see if it is the same.
RSA3 is a simple extractor checker program that allows you to rule out extract problems in R/3. It is simple to use, but only really tells you if the extractor works. Since records that get updated into Cubes/ODS structures are controlled by Update Rules, you will not be able to determine what is in the Cube compared to what is in the R/3 environment. You will need to compare records on a 1:1 basis against records in R/3 transactions for the functional area in question. I would recommend enlisting the help of the end user community to assist since they presumably know the data.
To use RSA3, go to it and enter the extractor ex: 2LIS_02_HDR. Click executes and you will see the record count, you can also go to display that data. You are not modifying anything so what you do in RSA3 has no effect on data quality afterwards. However, it will not tell you how many records should be expected in BW for a given load. You have that information in the monitor RSMO during and after data loads. From RSMO for a given load you can determine how many records were passed through the transfer rules from R/3, how many targets were updated, and how many records passed through the Update Rules. It also gives you error messages from the PSA.
Q) How can I copy queries from an info cube to another info cube in Business Explorer?
A) By using the Transaction RSZC in our BW system.
Q) What is the feature of Delta queue?
A) It collects the data from R/3 and store it within the delta queue in R/3 until next delta extract. The DataSource reads the Delta Queue data and push it to BW.
How do we see the data that’s collected and stored in the delta queue?
Go to Transaction RSA7 on R/3 to view the contents of the delta queue. Note only extractors that have been successfully initialized will show up in this queue
Q) what is the difference between V1, V2 and V3 updates?
A) >> V1 Update: It is a Synchronous update. Here the Statistics update is carried out at the same time as the document update (in the application tables).
>> V2 Update: It is an Asynchronous update. Statistics update and the Document update take place as different tasks.
V1 & V2 don’t need scheduling.
>> Serialized V3 Update: The V3 collective update must be scheduled as a job (via LBWE). Here, document data is collected in the order it was created and transferred into the BW as a batch job. The transfer sequence may not be the same as the order in which the data was created in all scenarios. V3 update only processes the update data that is successfully processed with the V2 update.
Q) What is compression?
It is a process used to delete the Request IDs and this saves space
Q) what is Rollup?
This is used to load new DataPackages (requests) into the InfoCube aggregates. If we have not performed a rollup then the new InfoCube data will not be available while reporting on the aggregate.
Q) What is the transaction for the Administrator work bench?
A) Transaction RSA 1
Q) The BEx Web Analyzer:
A) The BEx Web Analyzer is a standalone, convenient Web application for data analysis that you can call using a URL or as an iView in the portal.
The Web Analyzer allows you to execute ad hoc analyses on the Web: When you have selected a data provider
(query, query view, InfoProvider, external data source), the data is displayed in a table with a navigation pane.
You can navigate to the data and use other Web Analyzer functions available in the application toolbar. For
example, you can change the type of data display, use the information broadcasting functions to broadcast
your analyses to others, and create printable versions of your analyses.
In the Web Analyzer, you can save the data view generated from navigation and analysis as a query view by
choosing Save View in the context menu, and you can save the ad hoc analysis by choosing Save As. When
the query view is saved, only the data view is saved; when the ad hoc analysis is saved, the entire Web
application is saved, including the properties of Web items and the layout of the data.
Q) Where can you implement currency translations?
A) Query definition or Query Run Time or Transformation Rules.
Q) What must be in place before you are able to define ‘Exception Cells’ in the query definition?
A) Structures, one in rows and one in columns, when you define selection criteria and formulas for structural components and there are two structural components of a query, generic cell definitions are created at the intersection of the structural components that determine the values to be presented in the cell.
Cell-specific definitions allow you to define explicit formulas and selection conditions for cells as well as implicit cell definitions. This means that you can override implicitly created cell values. This function allows you to design much more detailed queries.
You can define exception cells only for queries that have two structures. For example, you can use
characteristic values in one structure and key figures in the other. You can then define cells if these
prerequisites have been met.
A cell is the intersection between two structural components. The term cell for the function Defining Exception Cells should not be confused with the term cell in Microsoft Excel. The formulas or selection conditions that you define for a cell always take effect at the intersection between two structural components. If a drilldown characteristic has two different characteristic values, the cell definition always takes effect at the intersection between the characteristic value and the key figure.
Q) About Attributes.
A) 1. Attributes are stored against Characteristic in BI.
2. There are two types of Attributes Text and Navigation
3. Navigation Attributes provide functionality similar to characteristic in query definition.
Attributes are part of Master Data and not Meta Data.
Characteristic attributes can be converted into navigation attributes. They can be selected in the query in exactly the same way as the characteristics for an InfoCube. In this case, a new edge/dimension is added to the InfoCube. During the data selection for the query, the data manager connects the InfoProvider and the master data table (‘join’) in order to fill the Query.
e.g. If you need the costs of the cost center drilled down by person responsible:
You use the attribute ‘Cost Center Manager’ for the characteristic ‘Cost Center’. If you want to navigate in the query using the cost center manager, you have to create the attribute ‘Cost Center Manager’ as a navigation attribute, and flag it as a navigation characteristic in the InfoProvider.
When executing the query there is no difference between navigation attributes and the characteristics for an InfoCube. All navigation functions in the OLAP processor are also possible for navigation attributes.
Q. What is the definition of a restricted key Figure?
A) Basic key figure of the Infoprovider that has been restricted by one or more characteristic selections.
You can restrict the key figures of an InfoProvider for reuse by selecting one or more characteristics. The key figures that are restricted by one or more characteristic selections can be basic key figures, calculated key figures, or key figures that are already restricted.
Q) Use of Calculated Key Figures?
A) 1. Calculated Key Figures can be stored at Infoprovider level.
2. Calculated Key Figures can be stored at Query level
In the Query Designer, you use formulas to recalculate the key figures in an InfoProvider so that you can reuse them. Calculated key figures consist of formula definitions containing basic key figures, restricted key figures or pre-calculated key figures.
If you define a calculated key figure at the InfoProvider level, you can use this calculated key figure in all queries based on this InfoProvider by moving the key figure into the rows or columns of the query using drag and drop.
If you define a Calculated Key Figure at the Query level, it is valid only for the Query in question and cannot be resued.
Q) Your company wants to consolidate Cost Center data from an SAP system and an external system via a file interface. In the legacy system, the cost Center number is 13 characters long but the SAP system only allows 10 characters. Which one of the following approaches would you use recommend.
A) Change the delivered content object 0COSTCENTER.
Unlike other SAP products, versioning allows both a customer version and SAP version of the same object, and they can be different.
This approach leads to faster implementations and is generally taken in ‘real life’ projects.
Q) Why do we need to normalize a data model?
A) Data normalization is a process in which data attributes within a data model are organized to increase the cohesion of entity types. In other words, the goal of data normalization is to reduce and even eliminate data redundancy, The advantage of having a highly normalized data schema is that information is stored in one place and one place only, reducing the possibility of inconsistent data.
Please note that in the extended star schema only the Fact Table (and not dimension table) is normalized.
Q) Aggregates can be created for which of the following?
A) Aggregates can be created only for InfoCubes. You can create multiple aggregates against the same infocube.
Q) Aggregates can be automatically proposed by the BI system. Which of the following options are available?
A) Propose from Query and Propose from BI Statistics.
You can choose Proposals in the menu if you want the system to propose aggregates. You have the following options:
● Proposals from queries: The system considers the queries that are created for an InfoCube.
● Proposals from the previous navigation: The system evaluates the last navigational step that you carried out with a query.
● Proposals from BI Statistics (tables): The system considers BI statistical data (database tables).
● Proposals from BI Statistics (InfoCube): The system considers the data that is contained in the BI Statistics InfoCube.
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