Usage of write optimized DSO's (WDSO's)

Write optimized DSO's can be really useful, not only for an acquisition layer in a BW system architecture.

For full loads a WDSO is ideal since data do not have to be activated. This means great performance improvements. No change log is filled either causing duplicate DB storage for every load. (unless you would clear the changelog after each load)

If you use a particular table only for lookups from other transformations, please notice the use of a proper index.

Be ware of the switch for uniqueness of data check. Standardly this is switched off, meaning during the load towards the WDSO the data in the load is being checked for uniqueness on the fields entered in the semantic key. Be aware, the DTP below will have semantic grouping switched on to be able to do this uniqueness check. This can have performance issues in bigger full loads when preparing the datapackages. Also the WDSO will automatically create an index on the fields in the Semantic Key,

Switching this option in the WDSO will enable you to freely load towards the object, but make the load towards the object "dummy" proof. Also, the table will have no index yet, you have to create one your own if needed.

Reactivate Transformations and DTP's

Are you also annoyed after changing an infoprovider (even description) that all transformations / DTP's are inactive?

Instead of manually reactivating them, you can also use program RSDG_TRFN_ACTIVATE to activate all inactive transformations (object status INA)...or activate transformation ID individually. Their related DTP's are then activated as well.

Finding objects in transports

For a major project it might be difficult to find the BW objects/Infoprovider that you have put in all of your transports.

It can be handy to check table E70 for all of your transport (+ subtransports!) technical names and then use table E071 to find all your objects.

Checking Query Defintion in SAP GUI

With program RSRQ_QUERYDEFINITION it is possible to have a look at the query definition in de SAP GUI.

It gives you an overview of the Filters / Rows/ Columns, Cells, Variables etcetera.

Upgrade Issues BW 7.3 SP5

Quickly I would like to share some technical lessons learned from the upgrade at a customer that i work for:

- SID generation now checks if characteristic value is valid for conversion routine of infoobject.This could potentially show problems in your datamodel. Please perform a regular delta load in a test system to avoid surprises after upgrade.

- Masterdata activation has changed in 7.3, we encountered a few issues with deadlocks during activation/SID generation. (1637633 note)

- Data activation in DSO's is/was a bit instable after upgrade. Also, no real improvement on data activation can be measured so far.

- Many problems with JAVA Web frontend, please test thoroughly. Many notes are already available since SP5. (also IP issues)

- Start/End routines of transformations are changed, now fields should be selected induvidually. Note 1635588 imported to fix issue with conversion 7.0 > 7.3 transformation with start/endroutines.

- Semantic key of DTP towards Infoobject should now be selected, otherwise no parallel loading can take place.

- Upgrading JAVA stack was really troublesome for SAP Basis team.

- Vague error messages when loading towards a cube with SID generation..check notes 1639786, 1657854 and 1664648.

Some nice new features:

- Skip button in process chains
- Drag and drop DTP's and Infopackages to proces chains
- Proces chain hierarchy when using local chains

- Extra checks when releasing transports

- Documentation of objects improved

- Version management of BW objects

- Hierarchy view in proces chains

Handy overview of data calculation function modules SAP

Below link goes to a wiki of SAP containing a listof usefull function modules to use for data calculations in transformations.

http://wiki.sdn.sap.com/wiki/display/ABAP/Function+Module+related+on+Date+calculations

Feel free to add more. :)

Generating Queries issue BW

Due to an issue in one of the latest support packs (in our case SP08), many queries were being generated on each call of an enduser.

This causes major performance issues in reporting in our system. Mainly in generating the variable screen and the (non) usage of cache for these queries.

Wonder if this is happening in your system? Check on table RSRREPDIR and check if the timestamp in field GENTIME is not too recent for your active queries.

Also in the system you will see if you trace the call of the report that tables D010TAB and D010INC are accessed many times.

Implementing note 1528921 helped out on this (Queries regenerated each time during

execution). Please be aware!