Message-ID: <4C58007E.4010909@tech.sdb.it>
Date: Tue, 03 Aug 2010 13:41:50 +0200
From: Silvio Brandani <silvio.brandani@tech.sdb.it>
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To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-admin@postgresql.org
Subject: Re: performance problems on Delete
References: <4C567A2E0200002500033FF1@gw.wicourts.gov>
In-Reply-To: <4C567A2E0200002500033FF1@gw.wicourts.gov>
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Kevin Grittner ha scritto:
> Silvio Brandani  wrote:
>  
>   
>> we have a performance issue on deleting data from a table.
>>
>> the delete is on the index key so should be very fast but the table
>> have 13 contraints of type foreign keys and the slowness seems due
>> to all the works done with the constraint.
>> Trying to drop the constraint and execute the delete the result is
>> immediate.
>>     
>  
> The usual reason for this is that you don't have indexes on the
> referencing columns, so to check whether the delete is OK it has to
> scan the related tables.  Think about what rows need to be checked to
> determine whether the delete is allowed and index the columns which
> will allow fast access to them.
>  
> -Kevin
>
>   
yes,
you where right , an index was missing.

thanks a lot

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