Unlogged Deletes in DB2/390 (or zOS)

[peter]

Hi All,
a quick question.

I haven't used DB2 on mainframe since 1995 so my memory is fading a
bit. But I seem to recall DB2/MVS having the ability to perform
unlogged deletes.

Situation is I have an oracle partition with 500M rows in it and I need
to update 60M rows and I expect the logging of updates will be too
much...I had proposed that the rows be deleted using unlogged deletes
and then the new images loaded. But I am told oracle does not support
unlogged deletes. So I was just wondering, is my memory of DB2 accurate
in allowing unlogged deletes, or am I just dreaming of the good old
days before everyone bought Oracle all the time...;-)

(Sybase IQ is the only database I know that lets me to unlogged
updates. (Though perhaps DB2 does that now???) )

Thanks

Peter

[Walter Schneider]

Hello,

as far as I'm aware, DB2 for MVS (now called z/OS) never allowed unlogged
SQL updates/deletes, and the recent versions still allow it for temporary
tables only. What you can do to efficiently delete millions of rows without
filling up your logs, is running the REORG utility with the DISCARD and LOG
NO options in effect. If the filter capabilities of DISCARD do not suit your
needs to identify the rows to be deleted (e.g. because you have to do
subselects or joins to other tables), you may also use the DSNTIAUL sample
unload program to extract the rows NOT to be deleted and then load them back
with LOAD REPLACE LOG NO.

Cheers - Walter.
<pe***@peternolan.com> schrieb im Newsbeitrag
news:11**********************@z14g2000cwz.googlegr oups.com...

Hi All,
a quick question.

I haven't used DB2 on mainframe since 1995 so my memory is fading a
bit. But I seem to recall DB2/MVS having the ability to perform
unlogged deletes.

Situation is I have an oracle partition with 500M rows in it and I need
to update 60M rows and I expect the logging of updates will be too
much...I had proposed that the rows be deleted using unlogged deletes
and then the new images loaded. But I am told oracle does not support
unlogged deletes. So I was just wondering, is my memory of DB2 accurate
in allowing unlogged deletes, or am I just dreaming of the good old
days before everyone bought Oracle all the time...;-)

(Sybase IQ is the only database I know that lets me to unlogged
updates. (Though perhaps DB2 does that now???) )

Thanks

Peter