On Sun, 26 Oct 2003 00:13:36 +0300, Hannu Krosing <[EMAIL PROTECTED]> wrote:
>UPDATE baz
> SET customer_id = '1234'
> WHERE baz_key IN (
> SELECT baz_key
> FROM baz innerbaz
> WHERE customer_id IS NULL
> and innerbaz.baz_key = baz.baz_key
> LIMIT 1000 );
AFAICS this is not what the OP intended. It is equivalent to
UPDATE baz
SET customer_id = '1234'
WHERE customer_id IS NULL;
because the subselect is now correlated to the outer query and is
evaluated for each row of the outer query which makes the LIMIT clause
ineffective.
Servus
Manfred
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
