Re: Materialized views in Oracle

Hello,
..
> up front, I'm not a database expert by any means and I'm nowhere close
> to an Oracle expert, or even an Oracle novice. If Oracle was a
> swimming pool, I would have those little floaty duck things on my
> arms.
Please go through this link
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::NO::P11_QUESTION_ID:15695764787749
Going through this and other queries/replies from Tom helps much more than
going through Oracle documentation. Tom is far more helpful than the
floaty ducks.
By the way, I have used MVs in Oracle for a long time and did not run into
major issues with them. But I started working with Oracle sometime ago. So
what comes across as 'strange' SQL to non-Oracle users is 'very normal'
SQL for me:).
Do be careful with on COMMIT FAST REFRESH MVs in OLTP systems.

See..
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:4541191739042

"
4) basically, your commits will tend to serialize. Whether this is an
issue depends on how long your materialized view takes to refresh itself.
Remember - the commits will serialize - not entire transactions, just the
very end of them. "

"As mentioned above, materialized views typically add overhead to
individual transactions and, if created with REFRESH ON COMMIT, will
introduce contention. The overhead arises from the need to track the
changes made by a transaction, these changes will either be maintained in
the session state or in log tables. In a high end OLTP system, this
overhead is not desirable. "

Regards,
Jayadevan

DISCLAIMER:

"The information in this e-mail and any attachment is intended only for
the person to whom it is addressed and may contain confidential and/or
privileged material. If you have received this e-mail in error, kindly
contact the sender and destroy all copies of the original communication.
IBS makes no warranty, express or implied, nor guarantees the accuracy,
adequacy or completeness of the information contained in this email or any
attachment and is not liable for any errors, defects, omissions, viruses
or for resultant loss or damage, if any, direct or indirect."