Thursday, 9 January 2014

SAP BI QUESTIONS & ANSWERS-5


SAP BI QUESTIONS & ANSWERS-5 :-


Q) Why does it take so long to delete from the delta queue (for example half a day) ?
A) Import PlugIn 2000.2 patch 3. With this patch the performance during deletion is considerably improved.

Q) Why is the delta queue not updated when you start the V3 update in the logistics cockpit area ?
A) It is most likely that a delta initialization had not yet run or that the delta initialization was not successful. A successful delta initialization (the corresponding request must have QM status 'green' in the BW System) is a prerequisite for the application data being written in the delta queue.

Q) What is the relationship between RSA7 and the qRFC monitor (Transaction SMQ1) ?
A) The qRFC monitor basically displays the same data as RSA7. The internal queue name must be used for selection on the initial screen of the qRFC monitor. This is made up of the prefix 'BW, the client and the short name of the DataSource. For DataSources whose name are 19 characters long or shorter, the short name corresponds to the name of the DataSource. For DataSources whose name is longer than 19 characters (for delta-capable DataSources only possible as of PlugIn 2001.1) the short name is assigned in table ROOSSHORTN.
In the qRFC monitor you cannot distinguish between repeatable and new LUWs. Moreover, the data of a LUW is displayed in an unstructured manner there.

Q) Why are the data in the delta queue although the V3 update was not started ?
A) Data was posted in background. Then, the records are updated directly in the delta queue (RSA7). This happens in particular during automatic goods receipt posting (MRRS). There is no duplicate transfer of records to the BW system. See Note 417189.

Q) Why does button 'Repeatable' on the RSA7 data details screen not only show data loaded into BW during the last delta but also data that were newly added, i.e. 'pure' delta records ?
A) Was programmed in a way that the request in repeat mode fetches both actually repeatable (old) data and new data from the source system.

Q) I loaded several delta inits with various selections. For which one is the delta loaded ?
A) For delta, all selections made via delta inits are summed up. This means, a delta for the 'total' of all delta initializations is loaded.

Q) How many selections for delta inits are possible in the system ?

A) With simple selections (intervals without complicated join conditions or single values), you can make up to about 100 delta inits. It should not be more. With complicated selection conditions, it should be only up to 10-20 delta inits.
Reason: With many selection conditions that are joined in a complicated way, too many 'where' lines are generated in the generated ABAP source code that may exceed the memory limit.

Q) I intend to copy the source system, i.e. make a client copy. What will happen with may delta? Should I initialize again after that ?
A) Before you copy a source client or source system, make sure that your deltas have been fetched from the DeltaQueue into BW and that no delta is pending. After the client copy, an inconsistency might occur between BW delta tables and the OLTP delta tables as described in Note 405943. After the client copy, Table ROOSPRMSC will probably be empty in the OLTP since this table is client-independent. After the system copy, the table will contain the entries with the old logical system name that are no longer useful for further delta loading from the new logical system. The delta must be initialized in any case since delta depends on both the BW system and the source system. Even if no dump 'MESSAGE_TYPE_X' occurs in BW when editing or creating an InfoPackage, you should expect that the delta have to be initialized after the copy.

Q) Is it allowed in Transaction SMQ1 to use the functions for manual control of processes ?
A) Use SMQ1 as an instrument for diagnosis and control only. Make changes to BW queues only after informing the BW Support or only if this is explicitly requested in a note for component 'BC-BW' or 'BW-WHM-SAPI'.

Q) Despite of the delta request being started after completion of the collective run (V3 update), it does not contain all documents. Only another delta request loads the missing documents into BW. What is the cause for this "splitting"?
A) The collective run submits the open V2 documents for processing to the task handler, which processes them in one or several parallel update processes in an asynchronous way. For this reason, plan a sufficiently large "safety time window" between the end of the collective run in the source system and the start of the delta request in BW. An alternative solution where this problem does not occur is described in Note 505700.

Q) Despite my deleting the delta init, LUWs are still written into the DeltaQueue ?
A) In general, delta initializations and deletions of delta inits should always be carried out at a time when no posting takes place. Otherwise, buffer problems may occur: If a user started the internal mode at a time when the delta initialization was still active, he/she posts data into the queue even though the initialization had been deleted in the meantime. This is the case in your system.

Q) The extract structure was changed when the DeltaQueue was empty. Afterwards new delta records were written to the DeltaQueue. When loading the delta into the PSA, it shows that some fields were moved. The same result occurs when the contents of the DeltaQueue are listed via the detail display. Why are the data displayed differently ? What can be done ?
A) Make sure that the change of the extract structure is also reflected in the database and that all servers are synchronized. We recommend to reset the buffers using Transaction $SYNC. If the extract structure change is not communicated synchronously to the server where delta records are being created, the records are written with the old structure until the new structure has been generated. This may have disastrous consequences for the delta. When the problem occurs, the delta needs to be re-initialized.

Q) How and where can I control whether a repeat delta is requested ?

A) Via the status of the last delta in the BW Request Monitor. If the request is RED, the next load will be of type 'Repeat'. If you need to repeat the last load for certain reasons, set the request in the monitor to red manually. For the contents of the repeat see Question 14. Delta requests set to red despite of data being already updated lead to duplicate records in a subsequent repeat, if they have not been deleted from the data targets concerned before.

Q) As of PI 2003.1, the Logistic Cockpit offers various types of update methods. Which update method is recommended in logistics ? According to which criteria should the decision be made? How can I choose an update method in logistics ? 

A) See the recommendation in Note 505700.

Q) Are there particular recommendations regarding the data volume the DeltaQueue may grow to without facing the danger of a read failure due to memory problems ?
A) There is no strict limit (except for the restricted number range of the 24-digit QCOUNT counter in the LUW management table - which is of no practical importance, however - or the restrictions regarding the volume and number of records in a database table).
When estimating "smooth" limits, both the number of LUWs is important and the average data volume per LUW. As a rule, we recommend to bundle data (usually documents) already when writing to the DeltaQueue to keep number of LUWs small (partly this can be set in the applications, e.g. in the Logistics Cockpit). The data volume of a single LUW should not be considerably larger than 10% of the memory available to the work process for data extraction (in a 32-bit architecture with a memory volume of about 1GByte per work process, 100 Mbytes per LUW should not be exceeded). That limit is of rather small practical importance as well since a comparable limit already applies when writing to the DeltaQueue. If the limit is observed, correct reading is guaranteed in most cases.
If the number of LUWs cannot be reduced by bundling application transactions, you should at least make sure that the data are fetched from all connected BWs as quickly as possible. But for other, BW-specific, reasons, the frequency should not be higher than one DeltaRequest per hour.
To avoid memory problems, a program-internal limit ensures that never more than 1 million LUWs are read and fetched from the database per DeltaRequest. If this limit is reached within a request, the DeltaQueue must be emptied by several successive DeltaRequests. We recommend, however, to try not to reach that limit but trigger the fetching of data from the connected BWs already when the number of LUWs reaches a 5-digit value.

Q) I would like to display the date the data was uploaded on the report. Usually, we load the transactional data nightly. Is there any easy way to include this information on the report for users? So that they know the validity of the report.
A) If I understand your requirement correctly, you want to display the date on which data was loaded into the data target from which the report is being executed. If it is so, configure your workbook to display the text elements in the report. This displays the relevance of data field, which is the date on which the data load has taken place.

Q) Can we load data directly into infoobject with out extraction is it possible.

A) Yes. We can copy from other infoobject if it is same. We load data from PSA if it is already in PSA.

Q) How many days can we keep the data in psa, if we r sheduled daily, weekly and monthly
A) We can set the time.

Q) How can u get the data from client if u r working on offshore projects. through which network.

A) VPN…………….Virtual Private Network, VPN is nothing but one sort of network where we can connect to the client systems sitting in offshore through RAS (Remote access server).



1 comment:

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