when your BW query takes 1 hour to run
I was stuck in this issue and I think I should share the knowledge out, just in case any of you face similar problems.
This issue happen because the Inventory cube is not compressed, and you’re building an aggregate over it, rollup takes long time, query runtime is extremely slow. You tell your user to restrict more selections when running the report, especially posting date/key dates try to put shorter duration. But the report is still so slow. Why? Because U do not have compression LOH.
What happens when you compress your data in Cube is that fact table lines will be transferred from F to E table. What significant outcome will you get by moving the data across another table? The answer is PERFORMANCE. Just follow the best practice :-
A maximum number of 20 – 30 partitions per f table are recommended (that figure comes from a “one load a day and 30 days a month” scenario).
Partitions on the E fact table may be more numerous because in queries there usually will be time restrictions that reduce the number of partition accesses (partition pruning) because the partitions on the E facttable are by some time criterion (OCALMONTH or 0FISCPER).
On the F table, every partition must be accessed for every query because there is no effective restriction on the p-dimension partitioning key on the F facttable, and due to load performance the Indexes on the F table are all local indexes. This will cause unacceptable query response times if there are too many partitions.
What is wrong with the current architecture is… there is no compression! we overcome slow query runtime by implementing aggregates, aggregates and aggregates. We have even aggregates with mean value 2 with Valuation —–|
So the best approach is to use simple technique like compression. Aggregation gives even more problem. I later found out why the previous consultants from 1 of the Big 4 did not use Compression is because “the value went wrong after compression” hence they avoided compression until now. I wonder where these Big 4 get their SAP CONsultants from, primary school?







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