Re: Join with a global temp table
From: Robert Klemme <shortcutter_at_googlemail.com>
Date: Sun, 01 Mar 2009 19:08:49 +0100
Message-ID: <71019tFhd7miU1_at_mid.individual.net>
On 01.03.2009 18:19, Chris Seidel wrote:
> I want to join a global temp table (delete on commit, not more than 250.000
> records) with a normal table (about 100 mio records).
>
> To speed up the join - would it be better to create a primary key on the
> join column of the temp table?
>
> My tests show that it seems not to affect the join performance - but my test
> system has only 200.000 records in the normal table.
>
> I'm asking because the PK on the temp table slows down the inserts to the
> temp table quite much (factor 2 - 3).
Date: Sun, 01 Mar 2009 19:08:49 +0100
Message-ID: <71019tFhd7miU1_at_mid.individual.net>
On 01.03.2009 18:19, Chris Seidel wrote:
> I want to join a global temp table (delete on commit, not more than 250.000
> records) with a normal table (about 100 mio records).
>
> To speed up the join - would it be better to create a primary key on the
> join column of the temp table?
>
> My tests show that it seems not to affect the join performance - but my test
> system has only 200.000 records in the normal table.
>
> I'm asking because the PK on the temp table slows down the inserts to the
> temp table quite much (factor 2 - 3).
Difficult to answer. I suggest, you post Oracle version along with the table DDL and the join you are doing. An execution plan would also be helpful.
Cheers
robert Received on Sun Mar 01 2009 - 12:08:49 CST