RE: Row Migration

From: Larry Elkins <elkinsl_at_flash.net>
Date: Fri, 27 Dec 2002 03:38:38 -0800
Message-ID: <F001.00522F11.20021227033838@fatcity.com>

Someone asked in a back channel email if parallelism is used. The select portion of the update statement uses parallelism (though the updates themselves get serialized) through the use of an in-line join update (to avoid the second sub-query commonly used to constrain the rows being updated):

Update (Select /*+ parallel hints */ ....

        From   a,b
        Where  a.key = b.key)

Set a.col1 = b.col1,

    a.col2 = b.col2
.....

Regards,

Larry G. Elkins
elkinsl_at_flash.net
214.954.1781

> -----Original Message-----
> From: root_at_fatcity.com [mailto:root_at_fatcity.com]On Behalf Of Larry
> Elkins
> Sent: Thursday, December 26, 2002 6:09 PM
> To: Multiple recipients of list ORACLE-L
> Subject: Row Migration
>
>
> Listers,
>
> 8.1.7.4 64 Bit Solaris
>
> Does row migration utilize DB File Sequential Reads on the table? Off the
> top of my head I would expect so, but I've never tested something
> like that
> before.

-- 
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-- 
Author: Larry Elkins
  INET: elkinsl_at_flash.net

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Received on Fri Dec 27 2002 - 05:38:38 CST