Antw: Re: Query questions

My version is 8.1.4. Here is the plan for the query, it's performed on a
smaller table, though because i can't access the biggest table at the
moment:
QUERY PLAN

-----------------------------------------------------------------------------------------------------------------------------

Bitmap Heap Scan on mytable (cost=67.48..16738.24 rows=6519 width=10)
(actual time=34.033..1903.106 rows=1 loops=1)
Recheck Cond: ((pid)::text = 'ZZZ000110011'::text)

Filter: ((crit)::text = '915677'::text)

-> Bitmap Index Scan on idx_pid_22 (cost=0.00..67.48 rows=8996
width=0) (actual time=12.998..12.998 rows=6207 loops=1)
Index Cond: ((pid)::text = 'ZZZ000110011'::text)

Total runtime: 1903.894 ms

And yes i have indexes on both pid (varchar(15)) and crit(varchar(13)).

>>> "A. Kretschmer" <andreas(dot)kretschmer(at)schollglas(dot)com> 31.07.06 15.49
Uhr >>>
am 31.07.2006, um 15:32:19 +0200 mailte Christian Rengstl folgendes:
> Hi list,
>
> i have a problem with creating a query and i hope somebody can give me
> some hints. I have the following table
> pid(varchar), crit(varchar), val1(varchar), val2(varchar),
> iDate(timestamp)
> where there are up to 63 million lines with 1500 distinct pids and
> around 42000 distinct crits:
> pid crit val1 val2 iDate
> 'yyy' 'aaa' 'b' 'c' someTime
> 'yyy' 'bbb' 'b' 'a' anotherTime
> ...
> What i have to do is to export the table for which i have to query the
> table with the following pattern: select val1, val2 from mytable where
> pid='yyy' and crit='aaa'. But if i do this 63 million times, it just
> takes too long. So, what i would like to do is to make a query where i

Do you have indexe on pid and crit?
Can you paste a "explain analyse select val1, val2 from mytable where
pid='yyy' and crit='aaa';"

Which version? ("select version();").

HTH, Andreas
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Andreas Kretschmer (Kontakt: siehe Header)
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