Hi,

At October 4, 2004, 08:43, Christian Kaufmann wrote:

> Hi,

> I have a delete statement like this:

> delete from A where AID in
> (select AID from B where TYP = 3 and PARENTID = 51)

> The two tables are in a 1:1 relationship. On table A and B I have a
> unique index on AID.

> Is there a way, to speed up such a query? In the plan I see, that the
> table A is accessed "NATURAL".

Try this:
delete from A
where exist(select 1 from B
where (TYP = 3) and (PARENTID = 51) and (B.AID=A.AID))

There probably is a way to increase the performance for the DELETE
statement that you are trying, but it would most likely require some
changes in Firebird's engine.

--
Best regards,
Daniel Rail
Senior System Engineer
ACCRA Group Inc. (www.accra.ca)
ACCRA Med Software Inc. (www.filopto.com)