Dear Pavneet ,
This is from Note - 407260.
Use the Function module to create / drop the secondary indexes.
You can create a program and use it in process chain.
This thread has more info on this : http://scn.sap.com/thread/354524
Hope it helpes.
- It is very important that either the 'P' or the primary index '0' on the E-facttable exists during the compression.
Please verify the existence of this index with transaction DB02. Without one of these indexes the compression will not run!!
If you are running queries parallel to the compression you have to leave the secondary indexes active.
If you encounter the error ORA-4030 during the compression you should drop the secondary indexes on the e-facttable. This can be achieved by using transaction SE14. If you are using the tabstrip in the adminstrator workbench the secondary indexes on the f-facttable will be dropped, too. (If there are requests which are smaller than 10 percent of f-facttable then the indexes on the f-facttable should be active because then the reading of the requests can be speed up by using the secondary index on the package dimension.) After that you should start the compression again.
Deleting the secondary indexes on the E facttable of an infocube that should be compressed may be useful (somemtimes even necessary) to prevent ressource shortages on the database. Since the secondary indexes are needed for reporting (not for compression) , queries may take much longer in the time when the secondary E table indexes are not there.
If you want to delete the secondary indexes only on the E facttable, you should use the function RSDU_INFOCUBE_INDEXES_DROP (and specify the parameters I_INFOCUBE = <techn. cubename> and I_FACTTAB = <name of E facttable>). If you want to rebuild the indexes use the function RSDU_INFOCUBE_INDEXES_REPAIR (same parameter as above).
To check which indexes are there, you may use transaction RSRV and there select the elementary database check for the indexes of an infocube and its aggregates. That check is more informative than the lights on the performance tabstrip in the infocube maintenance.
- 7. As already stated above it is absolutely necessary, that a concatenated index over all dimensions exits. This index normally has the suffix 'P'. Without this index a compression is not possible! If that index does not exist, the compression tries to build it. If that fails (forwhatever reason) the compression terminates.
If you normally do not drop the secondary indexes during compression, then these indexes might degenerate after some compression-runs and therefore you should rebuild the indexes from time to time. Otherwise you might see performance degradation over time.
As the distribution of data of the E-facttable and the F-facttable is changed by a compression, the query performance can be influenced significantly. Normally compression should lead to a better performance but you have to take care, that the statistics are up to date, so that the optimizer can choose an appropriate access path. This means, that after the first compression of a significant amount of data the E-facttable of the cube should be analyzed, because otherwise the optimizer still assumes, that this table is empty. Because of the same reason you should not analyze the F-facttable if all the requests are compressed because then again the optimizer assumes that the F-facttable is empty. Therefore you should analyze the F-facttable when a normal amount of uncompressed requests is in the cube.
Please update the status, for learning.
Chanda.