How to clear all cached items in Oracle

sql oracle caching oracle10g
Kevin Babcock picture Kevin Babcock · Jan 27, 2010 · Viewed 96.2k times · Source

I'm tuning SQL queries on an Oracle database. I want to ensure that all cached items are cleared before running each query in order to prevent misleading performance results. I clear out the shared pool (to get rid of cached SQL/explain plans) and buffer cache (to get rid of cached data) by running the following commands:

alter system flush buffer_cache;
alter system flush shared_pool;

Is there more I should be doing, or is this sufficient?

Thanks!

Answer

Doug Porter picture Doug Porter · Jan 27, 2010

Flushing the shared pool should do it, but Tom Kyte lists a couple reasons below why you may not get the result you are expecting in some cases:

http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:6349391411093

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