Re: SQL challenge;-)

From: Tracy Carlson <tracy.carlson_at_oracle.com>
Date: Thu, 3 May 2001 16:39:38 -0700
Message-ID: <T4mI6.4$Wb3.1452@inet16.us.oracle.com>

Try the minus operator

Tracy Carlson
Oracle Support

"Frank an der Heiden" <fh_at_energotec.de> wrote in message news:9cq15i$e56$1_at_oxygen.technet.net...
> hi,
>
> here a little task for all sql-freaks ;-))
>
> i have to tables.
> these tables have the same structure.
> i want to check out which row of <column> of the first table is not
> existing in <column> of the second table.
>
> this sql-statement works:
>
> SELECT <column> FROM <table1> WHERE <column> NOT IN (SELECT <column> FROM
> <table2>);
>
> but it is very very slow, because the second select is done very often if
> you have many rows in table1.
> any simple idea for improving performance?
> a tried to use a join, but i wasn't able to bring it to work, maybe it's
too
> late ;-((
>
> good night
> frank
>
>
>
Received on Thu May 03 2001 - 18:39:38 CDT