What is a Materialized View?

A database object that stores the results of a query

–Marries the query rewrite features found in Oracle Discoverer with the data refresh capabilities of snapshots

Features/Capabilities

–Can be partitioned and indexed

–Can be queried directly

–Can have DML applied against it

–Several refresh options are available

–Best in read-intensive environments

 

Advantages

–Useful for summarizing, pre-computing, replicating and distributing data

–Faster access for expensive and complex joins

–Transparent to end-users

MVs can be added/dropped without invalidating coded SQL

Disadvantages

–Performance costs of maintaining the views

–Storage costs of maintaining the views