How to invalidate a SQL statement in the Oracle SQL area so that a new plan is produced when collecting statistics

Question

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, result

Answer 1

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.

Answer 2

If you are using 10.2.0.4 or later, you should be able to use the DBMS_SHARED_POOL package to purge a single cursor from the shared pool.