Alle 16:54, mercoledì 10 marzo 2004, hai scritto:
> Paolo Tavalazzi <ptavalazzi@charta.it> writes:
> > I have two query that they are different only for order of the tables
> > in FROM lclause , but give back different query plan :
>
> Hm, seems like the planner is making wacko estimates in the second case.
> You didn't say what data types are involved in this query --- are any of
> the join columns int8 or float8 or timestamp? If so you might be
> getting bitten by the 7.4 pg_statistic alignment bug. Please follow the
> repair procedures suggested in the 7.4.2 release notes:
> http://developer.postgresql.org/docs/postgres/release.html#RELEASE-7-4-2
> and see if that improves matters.
>
> regards, tom lane
I have applied the procedure for fixing pg_statistic as you had said, but the result is the same!
Only tran.time in the query is a timestamp , no int8 or float8.
The OS is FEDORA 0.96 x86_64 and the flag --enable-integer-datetimes is false,it could be a problem??
I don't know what to make, help me please!
Another question, in 7.4 GROUP BY clause not guarantee the ordering of result.
Can I desable the new group by algorithm to maintain the coherence whit the programs that I have in production with
pg_7.3
Thank you !!!