Thanks Hans,

that done the job....

There was a ) missing. I added it at the end of the statement,
correct?

Stefan

--- In firebird-support@yahoogroups.com, "Hans" <hhoogstraat@...>
wrote:

>
> Try maybe something like
>
> delete from businessclassesroot a where
> exists (select 1 from iwadisobject_lrutimeslot b where b.bold_id =

a.bold_id

> and not exists (select 1 from iwadisobject c where c.bold_id =

b.objects)

>
> The 'not in' clause can be expensive
>
> ----- Original Message -----
> From: "swestner" <s@...>
> To: <firebird-support@yahoogroups.com>
> Sent: Sunday, August 10, 2008 2:09 PM
> Subject: [firebird-support] Speedup delete-statement
>
>
> > Hello,
> >
> > does anybody know if there is an alternative to the following

select:

> >
> > delete from businessclassesroot where bold_id in
> > (select bold_id from iwadisobject_lrutimeslot where objects not in
> > (select bold_id from iwadisobject))
> >
> > It runs about an hour on a DB which have 30.000.000 entries in
> > businessclassesroot and iwadisobject.
> >
> > The actual plan is:
> >
> > PLAN (IWADISOBJECT NATURAL)
> > PLAN (IWADISOBJECT_LRUTIMESLOT INDEX

(IX_IWADISOBJECT_LRUTIMESL09I))

> > PLAN (BUSINESSCLASSESROOT NATURAL)
> >
> > There are indexes on ale columns which are used in the SQL.
> >
> > Thanks
> >
> > Stefan
> >
> >
> > ------------------------------------
> >
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >
> > Visit http://www.firebirdsql.org and click the Resources item
> > on the main (top) menu. Try Knowledgebase and FAQ links !
> >
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> >
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > Yahoo! Groups Links
> >
> >
> >
>