Re: [HACKERS] psql nested queries with 2000+ records - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] psql nested queries with 2000+ records
Date
Msg-id 199803201724.MAA08299@candle.pha.pa.us
Whole thread Raw
In response to psql nested queries with 2000+ records  (Coronach <coronach@hill-b-073.resnet.purdue.edu>)
Responses Re: [HACKERS] psql nested queries with 2000+ records
List pgsql-hackers
>
> I have noted with 2000+ records in a table (using a btree unique index on
> the primary key, btw) performance of a query takes 15+ minutes to respond.
>
> The query is in the structure of this
>
> select foo from bar where foo in (select foo from bar where bazzfoo like
> 'Word%');

Very strange.  15+ minutes?  Wow, that is terrible, even longer than a
sequential scan of the table.  Try EXPLAIN and tell us what it says in
the two cases.

>
> Just reporting a possible bug..
>
> With smaller amounts of records, responce time is within a few seconds.
>
> Other information you might want:
>
> postgres version: 6.3
> os: BSDI 3.1

Same OS here.
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