On 03/09/13 09:47, Craig Ringer wrote:
On 09/03/2013 03:46 PM, jesper@krogh.cc wrote:
Hi.
I have a strange situation where generating the query plan takes 6s+ and
executing it takes very little time.
How do you determine that it's planning time at fault here?
Not that I'm sure, but the timing I send were only for "explain" not "explain analyze". The database is constantly updating and at the moment i cannot reproduce it any more. But at the time I picked the numbers it were very reproducible.. (tried 10+ times over 15 minutes).
Please take separate timing for: PREPARE testq AS select table.id from db.table left join db.tablepro on db.id = tablepro.table_id where table.fts @@ to_tsquery('english','q12345') ; and then: EXPLAIN ANALYZE EXECUTE testq;
I'll try to do that if i see the problem re-occour. I'm just very interested in what explain then does if it is not only the time for the query plan. When I did try the "PREPARE / EXECUTE" dance as you described .. i didnt see the prepare state take time, which seems to be consistent with that the planning time is in the EXECUTE step according to the documentation.
--
Jesper