Maybe you can try:

Delete from tableA Where Exists(Select 1 from tableB where someval=’x’ and
tableA.ID=tableB.ID)

Michael



From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of Gordon Niessen
Sent: Monday, September 26, 2011 8:53 PM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Delete Performance Issue





I am using FB 1.5 and doing a delete from a large table using the
primary key as a reference from a sub select

delete from tableA where ID in (select ID from tableB where someval = 'x')
The subquery is fast and looks like it uses the index. But the plan for
the delete is (ID NATURAL) and take a minute to run.

Other then creating a stored procedure to do this, how can I improve the
query?

--
Thanks,

Gordon





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