Re: Slow update with simple query

From: Arnaud Lesauvage <thewild(at)freesurf(dot)fr>
To: Ragnar <gnari(at)hive(dot)is>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Slow update with simple query
Date: 2006-12-13 11:35:04
Message-ID: 457FE568.8010302@freesurf.fr
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Ragnar a écrit :
>> Do you think the problem is with the indexes ?
>
> I guess so. are you sure about the index on t1.uid?
> what are the column definitions for t1.uid and t2.uid ?
> are they the same ?

Man, no !!!
I just checked and indeed, no index on this column. I probably dropped
it lately.
Thanks Ragnar.
(t1.uid and t2.uid were the same, character(32) columns)

> you should ba able to get a plan similar to:
> Merge Join (cost=0.00..43.56 rows=1000 width=11)
> Merge Cond: ("outer".uid = "inner".uid)
> -> Index Scan using t1i on t1 (cost=0.00..38298.39 rows=2000035
> width=10)
> -> Index Scan using t2i on t2 (cost=0.00..26.73 rows=1000 width=5)
>
> what postgres version are you using ?

Ooops, forgot that too : 8.1.4

I am creating the index right now, I'll tell you if this fixes the problem.
Thanks for your help !

--
Arnaud

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