| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Arnaud Lesauvage <thewild(at)freesurf(dot)fr> |
| Cc: | Ragnar <gnari(at)hive(dot)is>, Jens Schipkowski <jens(dot)schipkowski(at)apus(dot)co(dot)at>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Slow update with simple query |
| Date: | 2006-12-13 16:46:25 |
| Message-ID: | 8399.1166028385@sss.pgh.pa.us |
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| Lists: | pgsql-performance |
Arnaud Lesauvage <thewild(at)freesurf(dot)fr> writes:
> Indeed, the new query does not perform that well :
> "Hash Join (cost=112.75..307504.97 rows=2024869 width=355) (actual time=53.995..246443.811 rows=2020061 loops=1)"
> ...
> "Total runtime: 2777844.892 ms"
> I removed all unnecessary indexes on t1 before running the query (I left the index on uid and the multicolumn index containind the updated field).
> I believe the multicolumn-functional-index computation is taking some time here, isn't it ?
Given that the plan itself only takes 246 sec, there's *something*
associated with row insertion that's eating the other 2500+ seconds.
Either index entry computation or constraint checking ...
regards, tom lane
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