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How to force INDEX UNIQUE SCAN to be used for a table?

in SQL Performance (MOSC) 6 commentsAnswered

Hi,

Oracle version: 19.19.0.0

Sometimes we meet a performance issue when deleting some records from a table. After checking the execution plan, the reason of the poor performance is one of its nested SQL is using "INDEX FAST FULL SCAN". We have to re-run gather statistics on the tables, and then manually flush the SQL execution plan cache. After all those manual actions, the execution plan for the nested SQL is changed to our desired "INDEX UNIQUE SCAN", and the delete record session can work well.

My question is, is there a way to force Oracle to use "INDEX UNIQUE SCAN" when deleting records from that table?

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