From: PFC <lists@boutiquenumerique.com>
To: arnaulist@andromeiberica.com
To: pgsql-performance@postgresql.org
Subject: Re: Advise about how to delete entries
Date: Fri, 02 Sep 2005 18:47:21 +0200
Message-ID: <op.swhh87t5th1vuj@localhost> (raw)
In-Reply-To: <43183AC9.1060704@andromeiberica.com>
References: <43183AC9.1060704@andromeiberica.com>
> "DELETE FROM statistics_sasme WHERE statistic_id = 9832;"
As Michael said, why use a NUMERIC when a bigint is faster and better for
your use case, as you only need an integer and not a fixed precision
decimal ?
Also if you use postgres < 8, the index will not be used if you search on
a type different from the column type. So, if your key is a bigint, you
should do WHERE statistic_id = 9832::bigint.
For mass deletes like this, you should use one of the following, which
will be faster :
DELETE FROM ... WHERE ID IN (list of values)
Don't put the 30000 values in the same query, but rather do 300 queries
with 100 values in each.
COPY FROM a file with all the ID's to delete, into a temporary table, and
do a joined delete to your main table (thus, only one query).
EXPLAIN DELETE is your friend.
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To: pgsql-performance@postgresql.org
Cc: lists@boutiquenumerique.com, arnaulist@andromeiberica.com
Subject: Re: Advise about how to delete entries
In-Reply-To: <op.swhh87t5th1vuj@localhost>
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