Thank you

This seems to be the fastes approch I have experienced.

Michael


--- In ib-support@yahoogroups.com, Svein Erling Tysvaer
<svein.erling.tysvaer@k...> wrote:

> At 12:03 18.03.2003 +0100, you wrote:
> >SELECT * FROM MYTABLE1 WHERE MYTABLE1.MYFIELD1 NOT IN (SELECT

MYFIELD1 FROM

> >MYTABLE2)
>
> This will work fine as long as you only have a few records in each

table,

> but the subselect is probably executed once for every row, so

you'll notice

> that this select will become slower as the number of records in the

tables

> increases. Generally, doing
>
> SELECT <whatever> FROM MYTABLE1 WHERE NOT EXISTS (SELECT 1 FROM

MYTABLE2

> WHERE MYTABLE2.<field> = MYTABLE1.<field>)
>
> is a lot quicker.
>
> HTH,
> Set