| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Teodor Sigaev <teodor(at)sigaev(dot)ru> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: GIN fast insert |
| Date: | 2009-02-11 15:05:11 |
| Message-ID: | 603c8f070902110705w259bcf59u2724aefa8d6c7ce7@mail.gmail.com |
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| Lists: | pgsql-hackers |
> I believe that user could get GIN's error about work_mem only intentionally:
> - turn off autovacuum
Meanwhile, in the other thread, we're having a discussion about people
wanting to do exactly this on a database-wide basis during peak load
hours...
> - set big work_mem
> - populate table with GIN index (by needed number of insertion)
> - prepare query which will return a lot of results (possibly, with
> seqscan=off because cost of scan of pending list grows fast)
> - decrease work_mem for at least ten times
> - execute query
Why would the new work_mem need to be 10x smaller than the old work mem?
...Robert
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