Give me a break....
From the URL:
"Table partitioning is a data organization scheme in which table data is divided across multiple
storage objects"
On the IBM i, the "storage object" used is called a member.
Reading on....
"Table partitioning offers easy roll-in and roll-out of table data, easier administration, flexible
index placement and better query processing.
Efficient roll-in and roll-out
Table partitioning allows for the efficient roll-in and roll-out of table data. You can achieve
this by using the ATTACH PARTITION and DETACH PARTITION clauses of the ALTER TABLE statement. Rolling
in partitioned table data allows a new range to be easily incorporated into a partitioned table as an
additional data partition. Rolling out partitioned table data allows you to easily separate ranges of
data from a partitioned table for subsequent purging or archiving.
Easier administration of large tables
Table level administration is more flexible because you can perform administrative tasks on
individual data partitions. These tasks include: detaching and reattaching of a data partition,
backing up and restoring individual data partitions, and reorganizing individual indexes. Time
consuming maintenance operations can be shortened by breaking them down into a series of smaller
operations. For example, backup operations can work data partition by data partition when the data
partitions are placed in separate table spaces. Thus, it is possible to backup one data partition of a
partitioned table at a time.
Flexible index placement
Indexes can now be placed in different table spaces allowing for more granular control of index
placement. Some benefits of this new design include:
* Improved performance of drop index and online index create.
* The ability to use different values for any of the table space characteristics between each
index on the table (for example, different page sizes for each index may be appropriate to ensure
better space utilization).
* Reduced IO contention providing more efficient concurrent access to the index data for the
table.
* When individual indexes are dropped space will immediately become available to the system
without the need for an index reorganization.
* If you choose to perform index reorganization, an individual index can be reorganized.
Both DMS and SMS table spaces support the use of indexes in a different location than the table.
Improved performance for business intelligence style queries
Query processing is enhanced to automatically eliminate data partitions based on predicates of the
query. This functionality, known as Data Partition Elimination, benefits many decision support
queries."
Now go back and find articles recommending the use of Multi-member physicals on the AS/400. Guess
what, the benefits list will match up quite nicely with the ones above.
Thus: multi-membered files are indeed "partitioned" tables as we know them today.
I'd be willing to bet that multi-member files have been around a lot longer.
Charles Wilt
Software Engineer
CINTAS Corporation - IT 92B
513.701.1307
wiltc@xxxxxxxxxx
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-
bounces@xxxxxxxxxxxx] On Behalf Of Dave Odom
Sent: Friday, April 25, 2008 4:47 PM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: Advice needed on a multimember DDS file to be converted
Rob, et al,
See the following as an example of what real table partitioning is:
http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ib
m.db2.udb.admin.doc/doc/c0021557.htm
This same architecture is how you partition each table (not "members" of
what the i5 community likes to call a "table" with "members") for the
rest of the real DBMS world (DB2, ORACLE and SQLServer).
Dave
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