| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Partitioning Question (1 of several)
Well, I'm certainly not the partitioning expert, but I think what it's saying is that if the index is partitioned differently from the table, then for index access paths, they are eligible for partition pruning, even if said pruning is not compatible with the table's partition scheme. This makes sense, since the index is global and partitioned, partition pruning can happen at index access time, then whatever index access operation is dictated, then the requisite table access by rowid to get any required data from the table. Since it's a global index, the rowids in the index entries from the index partition that was utilized, may point to any table rows in any table partition.
-Mark
-----Original Message-----
From: david wendelken [mailto:davewendelken_at_earthlink.net]
Sent: Monday, March 22, 2004 1:36 PM
To: oracle-l_at_freelists.org
Subject: Partitioning Question (1 of several)
"Partition pruning dramatically reduces the amount of data retrieved from disk and shortens the use of processing time, improving query performance and resource utilization. If you partition the index and table on different columns (with a global, partitioned index), partition pruning also eliminates index partitions even when the partitions of the underlying table cannot be eliminated."
I not positive I understand the second sentence. Could someone give an example?
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.htmlput 'unsubscribe' in the subject line.
-----------------------------------------------------------------
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request_at_freelists.org
 |
 |