Hi Sri,
(1) InfoObject Pruning: Using the APO Cube as your guide to "Which InfoObjects" do I really need in the solution, trim the number of InfoObjects contained in the WAPO down to only what APO needs ... as opposed to all the InfoObjects that the BW Cube can give you. The width of the records being processed does have a reasonable impact on general ETL loading.
(2) A further addition to (1) is to see of the DataSource definition in APO can be trimmed down to only ask for the InfoObjects you want in APO. A cube will offer many characteristics and key figures for reporting in BW that APO just won't care about ... so make sure your DataSource only takes what it needs.
(3) While write optomised DataStores are technically faster for "reduced time it takes to extract right now" they are actually a lot, lot slower in the grand scheme of your whole data flow path way. By considering the use of a standard DataStore in APO you will get a slow down because of the process of "Activating the requests" ... however the advantages are much, much better when you consider (a) the dataflow from that point onwards through APO is a TRUE delta (b) the activation process compressed and added the granularity difference between the DataSource (BW cube) versus the DataTarget (APO DataStore) (c) you can run the BW cube to APO DataStore extraction every night, effectively spreading the burden of the data volume over 7 nights instead of jamming it into 1 night once a week (d) using a standard DataStore in APO also offers better options for the support of the requests due to the ability to do repair full loads and have the activation generate true deltas while confirming the whole DataSet matches between DataSource and DataTarget.
(4) Consider introducing an InfoSource in APO directly after the DataSource and before the APO DataStore. The intention is to ensure you leverage the "Key Field" ticks on the InfoSource structure definition to match the key of the DataTarget (APO DataStore). The reason why you want to use the key field feature of InfoSources is that BW v7 will do an in-memory compression of the DataPacket as it flows through. This can introduce a significant improvement (without ABAP) as soon as possible into the ETL data flow when the DataSet in the DataProvider is significantly more granular than the DataSet definition in the DataTarget where it is going to live.
Hope this helps.
Kind regards,
John.