From: | Roberto Moreda <moreda(at)sanluis(dot)net> |
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To: | gpsql-general <pgsql-general(at)hub(dot)org> |
Subject: | Two questions about join performance |
Date: | 1999-08-06 00:14:49 |
Message-ID: | 19990806021449.A26825@sanluis.net |
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Thread: | |
Lists: | pgsql-general |
Sorry for being so reiterative :)
The planifier isn't perfect for many queries...
Is there any way (without touch C code) to tell explicitly the plan of a query
to Postgres?
How can I manage the problem of select a few rows with a boolean atribute
when they are 5 rows in a table of 100000 rows?
I't must to be an index, but
the optimizer asumes that a Seq Scan is more cheap... yes, yes... I know :
if I ask for the 100000 then Seq Scan is the solution, but the interesting
query is the other : to extract the 5 rows with flag='Y' from whitin the
100000 rows with the flag='N'.
I'm in a big trouble because of all this.
TIA again.
Roberto
--
Roberto Moreda
Resp. Dpto. Informática Handem/San Luis
Tlf +34 981 779000
Fax +34 981 779022
Pol. Piadela Sur, Autovía A6 Sal.567
15300 Betanzos (A Coruña) - España
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