Thanks for your answers.



The worst table has around 25 million records, of which 7-10 million
need to be deleted. For what you say it seems that the best option is to
drop the index, delete the records and recreate the index. I'll try
that.



Jordi.



________________________________

From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of Brenden Walker
Sent: Tuesday, May 29, 2007 8:51 PM
To: firebird-support@yahoogroups.com
Subject: RE: [firebird-support] MASSIVE DELETIONS

> -----Original Message-----
> From: firebird-support@yahoogroups.com

<mailto:firebird-support%40yahoogroups.com>

> [mailto:firebird-support@yahoogroups.com

<mailto:firebird-support%40yahoogroups.com> ] On Behalf Of

> Puigsegur, Jordi
>
> Which is the best way to perform a massive deletion on a
> table with million of rows ?
>
> In other environments we first perfom a select to gather the
> dbkeys of the records to be deleted and then delete them
> performing commits every n records. Is there something
> similar in Firebird ?

I think a lot depends on how massive the deletion. If I need to keep a
small percentage of records, I find that copying them to a temporary
table (possibly external) and then dropping/recreating the original
source table works very well. Dropping tables takes hardly any time.





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