RE: Partition Elimination

From: <dave.leach_at_paymaster.co.uk>
Date: Fri, 01 Jun 2001 02:48:10 -0700
Message-ID: <F001.0031779F.20010601013020@fatcity.com>

Many thanks for the replies on this.

I was indeed using autotrace instead of doing an explain plan with utlxpls. I have also found the detail I was looking for in the documentation (can't beleive I didn't seee it before, it must have been a long day!!).

Cheers,

Dave Leach

-----Original Message-----
Sent: 31 May 2001 18:22
To: Multiple recipients of list ORACLE-L

Oracle could be doing partition elimination but the tools that you are using to see the execution plan is not showing you the details you're looking for.

I usually do:

Truncate table plan_table;
explain plan for <your-sql>;
select * from plan_table;

There should be two columns that indicate the partition-start_number and the partition_stop_number for this full table scan.

If it's not working let's know.

Regards,

Waleed

-----Original Message-----
Sent: Thursday, May 31, 2001 12:01 PM
To: Multiple recipients of list ORACLE-L

Hi All,

Can anyone help me with this.

I have range partitioned a table (no indexes) and then computed statistics. I have now queried the table using the partition key as the only criteria in the where clause. Why does Oracle still do a full table scan, why is it not clever enough to only scan the partition(s) effected by the where condition?.

The Oracle documentation gives a good insight into partitioning but does not go into detail about when partition elimination will be performed and what the explain plan would look like when this occurs. If anyone can point me to a section of the documentation that covers this I would be grateful.

Many Thanks,

Dave Leach

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Author: Khedr, Waleed
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