Re: Unexplained Plan Change
- From: Stephane Faroult <sfaroult@xxxxxxxxxxxx>
- To: moabrivers@xxxxxxxxx
- Date: Mon, 21 Jun 2010 19:15:39 +0200
Not sure this is the case here, but I have seen in the past something
very similar coming from a "peeked" bind variable the value of which was
outside the bounds known by Oracle (low_value/high_value in
dba_tab_columns - stored in hexa, utl_raw and the like may be useful for
converting).
HTH
Stephane Faroult
RoughSea Ltd <http://www.roughsea.com>
Konagora <http://www.konagora.com>
RoughSea Channel on Youtube <http://www.youtube.com/user/roughsealtd>
LB wrote:
> I've got a query that ran this morning that for some reason decided to
> jump ship off its normal plan and use a different plan. This is a
> very straightforward single table query. When the query runs normally
> it uses the correct index and returns results very quickly. This
> table and its 2 indexes (one PK and one non-unique) have their
> respective statistics gathered nightly at 1AM. At 8AM this morning,
> Oracle decided that using the PK index was the best choice and so it
> gobbled up 22 seconds doing single block I/O. Now I understand that
> gathering statistics can cause a SQL plan to change but that plan
> change should remain effect all things being equal.
--
//www.freelists.org/webpage/oracle-l
Other related posts:
