BW--收集到BW的一些问答

 

Quiz: SAP BI/BW -- beginner level

1. The following transactions are relevant to the data sources in an SAP BW source system.

a. RSA3
b. RSA4
c. RSA5
d. RSA6

2. True or False? A reference characteristic will use the SID table and master data table of the referred characteristic.

a. True
b. False

3. The following statements are not true about navigational attributes.

a. An attribute of an info object cannot be made navigational if the attribute-only flag on the attribute info object has been checked.
b. Navigational attributes can be used to create aggregates.
c. It is possible to make a display attribute to navigational in an info cube data without deleting all the data from the info cube.
d. Once an attribute is made navigational in an info cube, it is possible to change it back to a display attribute if the data has been deleted from the info cube.

4. True or False? It is possible to create a key figure without assigning currency or unit.

a. True
b. False

5. The following statements are true for compounded info objects.

a. An info cube needs to contain all info objects of the compounded info object if it has been included in the info cube.
b. An info object cannot be included as a compounding object if it is defined as an attribute only.
c. An info object can be included as an attribute and a compounding object simultaneously.
d. The total length of a compounded info object cannot exceed 60.

6. The following statements are true for an info cube.

a. Each characteristic of info cube should be assigned to at least one dimension.
b. One characteristic can be assigned to more than one dimensions.
c. One dimension can have more than one characteristic.
d. More than one characteristic can be assigned to one line item dimension.

7. The following statements are true for info cubes and aggregates.

a. Requests cannot be deleted if info cubes are compressed.
b. A request cannot be deleted from an info cube if that request (is compressed) in the aggregates.
c. Deleting a request from the cube will delete the corresponding request from the aggregate, if the aggregate has not been compressed.
d. All of the above.

8. The following statements are true regarding the ODS request deletion.

a. It is not possible to delete a request from ODS after the request has been activated.
b. Deleting an (inactive) request will delete all requests that have been loaded into the ODS after this request was loaded.
c. Deleting an active request will delete the request from the change log table.
d. None of the above.

9. The following statements are true for aggregates.

a. An aggregate stores data of an info cube redundantly and persistently in a summarized form in the database.
b. An aggregate can be built on characteristics or navigational attributes from the info cube.
c. Aggregates enable queries to access data quickly for reporting.
d. None of the above.

10. True or False? If an info cube has active aggregates built on it, the new requests loaded will not be available for reporting until the rollup has been completed successfully.

a. True
b. False

11. What is the primary purpose of having multi-dimensional data models?

a. To deliver structured information that the business user can easily navigate by using any possible combination of business terms to show the KPIs.
b. To make it easier for developers to build applications, that will be helpful for the business users.
c. To make it easier to store data in the database and avoid redundancy.
d. All of the above.

12. The following statements are true for partitioning.

a. If a cube has been partitioned, the E table of the info cube will be partitioned on time.
b. The F table of the info cube is partitioned on request.
c. The PSA table is partitioned automatically with several requests on one partition.
d. It is not possible to partition the info cube after data has been loaded, unless all the data is deleted from the cube.

13. The following statements are true for OLAP CACHE.

a. Query navigation states and query results are stored in the application server memory.
b. If the same query has been executed by another user the result sets can be used if the global cache is active.
c. Reading query results from OLAP cache is faster than reading from the database.
d. Changing the query will invalidate the OLAP cache for that query.

14. The following statements are true about the communication structure.

a. It contains all the info objects that belong to an info source.
b. All the data is updated into the info cube with this structure.
c. It is dependent on the source system.
d. All of the above.

15. The following statements are untrue about ODSs.

a. It is possible to create ODSs without any data fields.
b. An ODS can have a maximum of 16 key fields.
c. Characteristics and key figures can be added as key fields in an ODS.
d. After creating and activating, an export data source is created automatically.

Correct answers:

Question #1: A, C, D
Transaction RSA3, or extractor checker, is used in the BW source system to check data sources for various extraction modes, including full update, delta update and delta initialization.

RSA5 is for installing standard business content data sources and RSA6 is for maintaining data sources.

Question #2: A
If an info object is created as a characteristic with a reference characteristic, it won't have its own sid and master data tables. The info object will always use the tables of the referred characteristic.

Question #3: D
All the statements except D are true. It is possible to change a navigational attribute back to a display attribute in an info cube, without deleting all data from the info cube.

Question #4: A
Yes, it is possible to create a key figure without assigning a unit if the data type is one of these four: Number, Integer, Date or Time.

Question #5: A, B, D
When a compounded info object is included in an info cube, all corresponding info objects are added to the info cube. If an info object is defined as an attribute, it cannot be included as compounding object. The total length of the compounding info objects cannot exceed 60 characters.

Question #6: A, C
Any characteristic in the info cube should be assigned to a dimension. One characteristic cannot be assigned to more than one dimension. One dimension can have more than one characteristic, provided it is not defined as a line item dimension.

Question #7: A, C
Once the info cubes are compressed it is not possible to delete data based on the requests. There won't be request IDs anymore. Requests can be deleted even if the requests in aggregates have been compressed. But the aggregates will have to be de-activated. Deleting an uncompressed request from an info cube will automatically delete the corresponding request from aggregate if the aggregate request has not been compressed.

Question #8: C
It is possible to delete requests from an ODS, even if the request has been activated. The "before and after image" of the data will be stored in the change log table using which the request will be deleted.

Deleting a request which has not been activated in ODS will not delete the requests which are loaded after this request. But if the request has been activated then the loaded and activated requests later will get deleted. Also the change log entries will be deleted for that request.

Question #9: A, B, C
Aggregates summarize and store data from an info cube. Characteristics and navigational attributes of an info cube can be used to create aggregates. Since aggregates contain summarized data, the amount of data in aggregates will be much less that the cube which makes the queries to run faster when they access aggregates.

Question #10: A
Newly-loaded requests in an info cube with aggregates will not be available for reporting until the aggregate rollup has been completed successfully. This is to make sure that the cube and aggregates are consistent while reporting.

Question #11: A
The primary purpose of multi-dimensional modeling is to present the business users in a way that corresponds their normal understanding of their business. They also provide a basis for easy access of data which is OLAP engine.

Question #12: A, B, C, D
BW allows partitioning of the info cubes based on time. If the info cube is partitioned, the e-fact table of the info cube will be partitioned on the time characteristic selected.

The F fact table is partitioned on request ids automatically during the loads. PSA tables are also partitioned during the loads and can accommodate more than one request. For an info cube to be partitioned, all data needs to be removed from the info cube.

Question #13: A, B, C, D
Query results are stored in the memory of application server, which can be retrieved later by another user running the same query. This will make the query faster since the results are already calculated and stored in the memory. By changing the query, the OLAP Cache gets invalidated.

Question #14: A, B
The communication structure contains all info objects in the info source and it is used to update the info cube by temporarily storing the data that needs to be updates to the data target. It doesn't depend on the source system.

Question #15: A, C
An ODS cannot be created without any data fields, and it can have a maximum of only 16 key fields. Key figures cannot be included as a key field in an ODS. The export data source is created after an ODS has been created and activated.

Quiz: SAP BI/BW -- intermediate level

1. Identify the statement(s) that is/are true. A change run...

a. Activates the new Master data and Hierarchy data
b. Aggregates are realigned and recalculated
c. Always reads data from the InfoCube to realign aggregates
d. Aggregates are not affected by change run

2. Which statement(s) is/are true about Multiproviders?

a. This is a virtual Infoprovider that does not store data
b. They can contain InfoCubes, ODSs, info objects and info sets
c. More than one info provider is required to build a Multiprovider
d It is similar to joining the data tables

3. The structure of the PSA table created for an info source will be...

a. Featuring the exact same structure as Transfer structure
b. Similar to the transfer rules
c. Similarly structured as the Communication structure
d. The same as Transfer structure, plus four more fields in the beginning

4. In BW, special characters are not permitted unless it has been defined using this transaction:

a. rrmx
b. rskc
c. rsa15
d. rrbs

5. Select the true statement(s) about info sources:

a. One info source can have more than one source system assigned to it
b. One info source can have more than one data source assigned to it provided the data sources are in different source systems
c. Communication structure is a part of an info source
d. None of the above

6. Select the statement(s) that is/are true about the data sources in a BW system:

a. If the hide field indicator is set in a data source, this field will not be transferred to BW even after replicating the data source
b. A field in a data source won't be usable unless the selection field indicator has been set in the data source
c. A field in an info package will not be visible for filtering unless the selection field has been checked in the data source
d. All of the above

7. Select the statement(s) which is/are true about the 'Control parameters for data transfer from the Source System':

a. The table used to store the control parameters is ROIDOCPRMS
b. Field max lines is the maximum number of records in a packet
c. Max Size is the maximum number of records that can be transferred to BW
d. All of the above

8. The indicator 'Do not condense requests into one request when activation takes place' during ODS activation applies to condensation of multiple requests into one request to store it in the active table of the ODS.

a. True
b. False

9. Select the statement(s) which is/are not true related to flat file uploads:

a. CSV and ASCII files can be uploaded
b. The table used to store the flat file load parameters is RSADMINC
c. The transaction for setting parameters for flat file upload is RSCUSTV7
d. None of the above

10. Which statement(s) is/are true related to Navigational attributes vs Dimensional attributes?

a. Dimensional attributes have a performance advantage over Navigational attributes for queries
b. Change history will be available if an attribute is defined as navigational
c. History of changes is available if an attribute is included as a characteristic in the cube
d. All of the above

11. When a Dimension is created as a line item dimension in a cube, Dimensions IDs will be same as that of SIDs.

a. True
b. False

12. Select the true statement(s) related to the start routine in the update rules:

a. All records in the data packet can be accessed
b. Variables declared in the global area is available for individual routines
c. Returncode greater than 0 will be abort the whole packet
d. None of the above

13. If a characteristic value has been entered in InfoCube-specific properties of an InfoCube, only these values can be loaded to the cube for that characteristic.

a. True
b. False

14. After any changes have been done to an info set it needs to be adjusted using transaction RSISET.

a. True
b. False

15. Select the true statement(s) about read modes in BW:

a. Read mode determines how the OLAP processor retrieves data during query execution and navigation
b. Three different types of read modes are available
c. Can be set only at individual query level
d. None of the above

Question #1: A, B
Change run activates the Master data and Hierarchy data changes. Before the activation of these changes, all the aggregates that are affected by these changes are realigned. Realignment is not necessarily done by reading InfoCubes. If these are part of another aggregate that can be used to read data for the realignment, change run uses that aggregate.

Question #2: A, B
Multiproviders are like virtual Infoproviders that do not store any data. Basic InfoCubes, ODSs, info sets or Info objects can be used to build a Multiprovider. Multiproviders can even be built on a single Infoprovider.

Question #3: D
The structure of PSA tables will have an initial four fields: request id, packet number, partition value and record number. The remaining fields will be exactly like Transfer Structure.

Question #4: B
Rskc is the transacation used to enter the permitted characters in BW.

Question #5: A, C
Info sources can be assigned to multiple source systems. Also, info sources can have multiple data sources within the same source system. Communication structure is a part of the source system.

Question #6: A, C
If the hide field is checked in a data source, that field will not be transferred to a BW system from the source system even after replication. If the selection field is not checked, that field won't be available for filtering the info package.

Question #7: A
ROIDOCPRMS is the table in the BW source system that is used to store the parameters for transferring data to BW. Max size is the size in KB which is used to calculate the number of records in each packet. Max lines is the maximum number of records in each packet.

Question #8: B
This indicator is used to make sure that the change log data is not compressed to one request when activating multiple requests at the same time. If these requests are combined to one request in change log table, individual deletion will not be possible.

Question #9: C
Transaction for setting flat file upload parameters is RSCUSTV6.

Question #10: A, C
Dimensional attributes have a performance advantage while running queries since the number of table joins will be less compared to navigational attributes. For navigational attributes, the history of changes will not be available. But for dimensional attributes, the InfoCube will have the change history.

Question #11: A
When a Dimension is created as a line item dimension, the SIDs of the characteristic is directly stored in the fact tables and these are used as Dimension IDs. Dimension table will be a view off of SID table and fact table.

Question #12: A, B, C
In the start routine, all records are available for processing. Variables declared in the global area can be used in individual routines. Returncode greater than 0 will abort processing of all records in the packet.

Question #13: A
If a constant is entered in the InfoCube-specific properties, only that value will be allowed in the InfoCube for that characteristic. This value will be fixed in the update rules and it is not possible to do the change in update rules for that characteristic.

Question #14: A
After makeing any type of change to an info set, it needs to be adjusted using the transaction RSISET.

Question #15: A, B
Read mode determines how an OLAP processor retrieves data during query execution and navigation. Three types of read modes are available:
1. Read data during expand hierarchies
2. Read data during navigation
3. Read data all at once
Read mode can be set at info provider level and query level.

Quiz: SAP BI/BW -- advanced level

1. Select the correct statements about the steps executed by a change run.

a. The steps activate the new master data and hierarchy data changes.
b. All aggregates are realigned and recalculated.
c. Aggregates containing navigational attributes are realigned and recalculated for the master data changes.
d. The steps delete the 'A' (active) records for which the 'M' (modified) records exist from master data tables, and makes all modified records active.
e. All of the above.

2. Key figures that are set for exception aggregation MIN or MAX in an aggregate cause the aggregates to be completely rebuilt for each change run alignment.

a. True
b. False

3. If special characters are not defined in transaction RSKC in BW then:

a. These characters cannot be loaded into BW at all.
b. These characters can only be loaded into text fields.
c. These characters can be loaded into attributes and texts.
d. BW won't be able to generate the SIDs for these characters because all the fields where SIDs are generated cannot be loaded.
e. None of the above.

4. A change run updates the 'E' table of the aggregates while doing the alignment for changes in the master data.

a. True
b. False

5. Select the correct statements related to the control parameters for a data transfer in table ROIDOCPRMS in the BW source system.

a. The field MAXSIZE is the maximum number of records which can be transferred to BW in a single packet.
b. The field MAXSIZE is the size in KB which is used to calculate the number of records per data packet.
c. MAXLINES is the maximum number of records which can be transferred to BW per data load.
d. If the number of data records per packet exceeds MAXLINES value the extraction process fails.

6. Identify the differences between an Infoset and a Multiprovider.

a. Both Multiproviders and Infosets can contain all the info providers in BW.
b. Queries built on Multiproviders use 'union' and queries on Infosets use 'join' to retrieve data from different info providers.
c. Both Multiproviders and Infosets do not have data, but data is accessed from the basic info providers used in these objects.
d. None of the above.

7. Select the correct statements about the OLAP Cache Monitor in BW.

a. The transaction for the OLAP Cache Monitor is RSRCACHE.
b. If the persistent mode is inactive then the cache is inactive and query results will not be cached in memory.
c. A 'read flag' is set in the Cache Monitor when data is read from the cache.
d. When new data is loaded into the info provider which the query is built on, the cache for that query is invalidated.
e. All of the above.

8. Select the correct statements about ODS settings.

a. Performance of the ODS activation improves when the BEx reporting flag is switched to off.
b. Overwriting a data record is not allowed if the 'unique' data record flag is set.
c. Data targets are updated from the ODS regardless of the ODS activation status.
d. All of the above.

9. It is not possible to activate an ODS which contains a request from a full load and a Delta Initialization load of the same data source.

a. True
b. False

10. Select the correct statements regarding data deletion settings in an InfoPackage.

a. It is possible to set an InfoPackage to delete all the data in an InfoCube during the loads.
b. Only uncompressed data can be set to be deleted from the cube in an InfoPackage during the loads.
c. Deletion settings can be done only for basic InfoCubes.
d. Data deletion settings in an InfoPackage are possible only for full loads.
e. All of the above.

11. Select the correct statements about parallel processing in Multiproviders.

a. Multiprovider queries create one process per info provider involved and are processed parallel by default.
b. It is not possible to make Multiprovider queries run sequential.
c. Multiprovider queries create a parent process which provides a synchronization point to collect the overall result from other sub processes.
d. Parallel processing is always faster than sequential processing in Multiproviders.
e. All of the above.

12. Select the correct statements about the ALPHA conversion routine in BW.

a. An ALPHA conversion routine is assigned to a characteristic info object automatically when it is created.
b. An ALPHA conversion routine is used to convert characteristic values from 'external to internal' values only.
c. Conversion is done on alphabets and numeric input values.
d. An ALPHA conversion routine removes the spaces on the right side of numeric values and right aligns them.
e. The left side of the numeric input values are filled with zeros.

13. Select the correct statements related to navigational attributes.

a. It is better to avoid using navigational attributes from a query performance point of view.
b.If a navigational attribute is used in an aggregate, the aggregate needs to be adjusted every time there is a change in the values of this attribute.
c. An attribute included as a characteristic in the InfoCube has the same effect as being used as a navigational attribute in the cube.
d. A navigational attribute can be made to display an attribute without removing data from the InfoCube.
e. None of the above.

14. A 'Check for Referential Integrity' can only be possible for information sources with flexible updating.

a. True
b. False

15. Select the correct statements about physical partitioning in BW.

a. New partitions on F table of an InfoCube are created during data loads to the InfoCube.
b. An E fact table is created when activating an InfoCube with a number of partitions corresponding to the partition value range.
c. If a cube is not partitioned before populating with data, it is not possible to partition the cube without removing all the data.
d. PSA table partitions can contain more than one request.
e. All of the above.

Question #1: A, C, D
Master data and hierarchy data changes are activated and all the aggregates which have navigational attributes which will be affected by the changes are realigned. Change run deletes all active records for which modified records exists in master data 'P' table and makes all modified records to active.

Question #2: A
If an aggregate contains key figures which are built as MIN or MAX, that will force a change run to recreate these aggregates during the alignment process.

Question #3: B, D
Unless specified using transaction RSKC, special characters cannot be loaded into BW fields where it needs to generte SIDs. So it is possible for these characters to be loaded into text fields.

Question #4: B
A change run doesn't update the 'E' table of the aggregates for the alignment of aggregates due to master data changes. The alignment is done by inserting rows with the necessary negative and positive key figure values in the 'F' table.

Question #5: B
In the table ROIDOCPRMS, MAXSIZE is the size in kilobytes which is used to calculate the number of records in each datapacket to be transferred to BW. If the calculated number of records exceeds MAXLINES, the packet size in terms of number of records will be made the same as the value of MAXLINES value.

Question #6: B, C
A Multiprovider can be built on basic InfoCubes, ODSs, info objects or Infosets. An Infoset can have only ODSs or info objects. Multiproviders use 'union' operation but Infosets use 'join'. Both the objects are logical definitions which don't store any data.

Question #7: A, C, D
Transaction RSRCACHE is for the Cache Monitor. The OLAP Cache will be active unless the 'cache inactive' flag is set. Persistent mode is to specify the action to be taken when the cache memory is exhausted.

Question #8: A, B
If the BEx Reporting flag is switched off than the SID won't have to be taken when activating the ODS. This improves performance. If the 'unique data records' flag is set, it is not possible to load records to the ODS for which the key combination already exists. Data targets can be updated only after the ODS activation takes place successfully.

Question #9: B
It is possible to activate an ODS which contains Delta and full loads from the same InfoSource if the full load is done with the repair flag set in the InfoPackage.

Question #10: A, C
All data can be set to be deleted from a basic cube during full loads and Delta loads. Data can be deleted depending on various conditions. Data can only be deleted from basic cubes, not the ODS.

Question #11: A, C
Multiprovider queries create processes to run on the individual info providers involved. These processes run parallel by default. The parent process provides a synchronization point to collect overall results from sub processes. Many times the parallel processing may be slower than sequential processing, if the data volume is high.

Question #12: A, D, E
The ALPHA conversion routine is assigned to the characteristic info objects when created. This needs to be deleted manually if not required. The conversion is applied to 'external to internal' formats and vice versa. For 'external to internal' formats, the values are right aligned and the spaces on left side is padded with zeros.

Question #13: A, B, D
Queries using navigational attributes will be slower since additional tables have to be joined with the Fact tables to get the desired results. If there are changes to the values of navigational attributes, the aggregates using these will have to be readjusted, which is done by a change run. Navigational attributes can be made to display only without removing the data from the cube.

Question #14: A
A referential integrity check is only possible for info sources with flexible updating

Question #15: E

The 'F' Fact table is partitioned on request and is created during data loads. The 'E' Fact table of the InfoCube is created with the number of partitions specified in the partitioning range. Once the data is loaded to the cube, partitioning based in the Time characteristic is not possible without removing the data. PSA table partitions can contain more than one request.

来源：http://searchsap.techtarget.com/general/0,295582,sid21_gci1182832,00.html