Re: Out of memory error in 8.1.0 Win32
От | Todd A. Cook |
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Тема | Re: Out of memory error in 8.1.0 Win32 |
Дата | |
Msg-id | 449AE968.9040609@blackducksoftware.com обсуждение исходный текст |
Ответ на | Re: Out of memory error in 8.1.0 Win32 (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Out of memory error in 8.1.0 Win32
Re: Out of memory error in 8.1.0 Win32 |
Список | pgsql-general |
Tom Lane wrote: > "Todd A. Cook" <tcook@blackducksoftware.com> writes: >> oom_test=> explain select val,count(*) from oom_tab group by val; >> QUERY PLAN >> ------------------------------------------------------------------------- >> HashAggregate (cost=1163446.13..1163448.63 rows=200 width=4) >> -> Seq Scan on oom_tab (cost=0.00..867748.42 rows=59139542 width=4) > >> The row estimitate for oom_tab is close to the actual value. Most of >> the values are unique, however, so the result should have around 59M >> rows too. > > Well, that's the problem right there :-(. Have you ANALYZEd this table? My production table and query are more complex. In the original, the query above was in a sub-select; the work-around was to create a temp table with the sub-query results, analyze it, and then do the larger query based off of the temp table. There have been off and on discussions on the pg lists about out of memory issues (see http://archives.postgresql.org/pgsql-bugs/2006-03/msg00102.php). I was just offering my test case as an example in case it might be of any use in tracking those problems down. :) -- todd
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