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ratnakar wrote:In Views, what happens is there is not data storage in it. Every time you execute the View, it has to pull the data using its query from the Base tables.
can any one tell me the use of materilized views in oracle?
explain briefly please...........
Materialized Views are replica (or Snapshot ) of data from some master site to another site.
It has the capability to store data. When you execute the MView it pulls data stored in it.
There is something called as MView Refresh which pulls data from the base tables and stores in this MView's storage unit. And when you read the MView data is pulled from this storage unit (and doesn't hit the base tables).
This somewhat ensures data availability always.
Please read this thoroughly... http://docs.oracle.com/cd/B28359_01/server.111/b28326/repmview.htm
ratnakar wrote:Usually, a materialized view is not just a copy of a table. Usually, some kind of transformation takes place. For example, a materialized view may countain the results of a GROUP BY on a table, or analytic functions applied to the table, or a join or tables, or a UNION of tables, or some combination of these kinds of things. Querying the materialized view can be much faster than querying a regular view (or the base tables) because much of the work is done when the materialized view is refreshed, before the query is performed.
THANKS FOR UR RESPONSE...
AND MV CONTAINS PHYSICAL DATA..BT WHAT IS THE USE OF THAT REPLICA.
You can learn about materialized views from the Database Concepts manual<a> and other documentation.
ratnakar wrote:Uses -
yes,..mv is replica bt what is the use...when we can use in real time scenarios...
1] Security : Outside access to base table data is restricted.
2] Availability : Data is always available and no need of executing queries every time and hitting Base Tables.
3] Faster data fetch.
4] Stores data after fetching and applying some business
Check this (nicely explained) --- http://docs.oracle.com/cd/B28359_01/server.111/b28326/repmview.htm#i44564
You can Google for more.. :-)
*@Frank* - Please rectify me if I'm wrong. I believe your words a lot.
Edited by: ranit B on Nov 24, 2012 9:02 PM
-- added link
-- added Note to Frank