Re: UPDATE problem
From: Michael Bialik <bialik_at_isdn.net.il>
Date: 9 Nov 2001 05:22:43 -0800
Message-ID: <969f8022.0111090522.26e8ca34_at_posting.google.com>
Date: 9 Nov 2001 05:22:43 -0800
Message-ID: <969f8022.0111090522.26e8ca34_at_posting.google.com>
Hi.
Try
UPDATE /*+ USE_NL(a) INDEX(a) */ tab1 a SET a.attrib_dest =
( SELECT b.attrib_source FROM tab2 b WHERE a.key = b.key ) WHERE tab1.key IN ( SELECT d.key FROM tab2 d WHERE d.attrib_source IS NOT NULL );
- You don't need to specify TAB1 in subselect of WHERE.
- There is a FULL TABLE SCAN on TAB2 ( IS NOT NULL can not use index ) so when dealing with 2 big table - it will take some time.
HTH. Michael. Received on Fri Nov 09 2001 - 14:22:43 CET