Home/ Questions/Q 6165535
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-23T22:10:59+00:00

I have a table and a query (within a PL/SQL packge) accessing that table.

  • 0

I have a table and a query (within a PL/SQL packge) accessing that table. Statistics are collected weekly normally.

A large update has been run on the table, resulting in significantly different data distribution on a particular indexed column. The query plan used by Oracle (which I can see from v$sqlarea) is sub-optimal. If I take an explain plan on the same* query from SQL*Plus, a good plan is returned.

I have since collected statistics on the table. Oracle is still using the query plan that it originally came up with. v$sqlarea.last_load_time suggests this was a plan generated prior to the statistics generation. I thought regenerating statistics would have invalidated plans in the SQL cache.

Is there any way to remove just this statement from the SQL cache?

(* Not character-for-character, matches-in-the-SQL-cache same, but the same statement).

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I found out (when researching something else) that what I should have done was to use

    no_invalidate => FALSE

    When collecting the statistics by calling gather_table_stats. This would have caused all SQL plans referencing the table to immediately be invalidated.

    The Oracle docs say:

    Does not invalidate the dependent cursors if set to TRUE. The procedure 
invalidates the dependent cursors immediately if set to FALSE. Use
DBMS_STATS.AUTO_INVALIDATE. to have Oracle decide when to invalidate dependent
cursors. This is the default.

    The default of AUTO_INVALIDATE seems to cause invalidation of SQL statements within the next 5 hours. This is to stop massive number of hard-parses if you are collecting statistics on lots of objects.

    • 0