This is an interesting tip which you will need when working on BW Query Specific Performance issues, you may have to delete a query from OLAP cache when you want to see a real performance of a query. Only when a query is deleted from OLAP cache, it will try to fetch the data from the database/disk which will result in the realistic runtime of a query, else the data will be fetched from OLAP cache which will be faster than the database access.
Here are the steps to delete a query from OLAP Cache
Step 1 : Go to transaction RSRT / RSRCACHE
Step 2 : If you are using RSRT Cache Monitor / else skip this step
Step 3 : Main Memory
Step 4 : Right click on the desired query and delete
Deleting a query from OLAP cache will not harm you, the only effect will be that very first time when the query is executed after the deletion from OLAP cache, it will run longer than expected (which is the goal of this article).
Thanks
PrakashP