Oracle materialized view index

How do you create an oracle view? When to use materialized view? What is Oracle unique index? Consequently, for best performance, create a single-column bitmap index on each materialized view key column.

In the case of materialized views containing only joins using fast refresh, create indexes on the columns that contain the rowids to improve the performance of the refresh operation. If you anticipate performing insert, update or delete operations on tables referenced by a materialized view concurrently with the refresh of that materialized view , and that materialized view includes joins and aggregation, Oracle recommends you use ON COMMIT fast refresh rather than ON DEMAND fast refresh. In the following example note how Oracle automatically adds an index to implement the system generated primary key we saw in the preceding topic, Constraints. How can I create index on this materialized view.

Keep in mind that Mviews have the same physical attributes of tables. So, for them, partitions, indexes and so on are managed on the same way. Materialize view is rebuilding index on a. You have to go for complete refreshes with union.

But you can fast refresh with union all. Once a clustered index is created you may create non-clustered indexes on the view. So each time the source table is update then the view gets update and the indexes are recompiled. Verify that the SET options for the session are set correctly before you create any tables and the view. Data warehouses frequently use a lot of bitmapped indexes.

For retrieving data from a materialized view , it makes sense to define a bitmapped index on each relevant column in a materialized view key. Indexes for retrieval. A materialized view is a database object that contains the of a query. It is different from simple view.

These materialized view have data stored and when you query the materialized view ,it returns data from the data stored. The FROM clause of the query can name tables, views, and other materialized views. You must have the privileges necessary to create these objects. Oracle Database uses these objects to maintain the materialized view data. Using materialized views against remote tables is the simplest way to achieve replication of data between sites.

In Oracle , if you specify REFRESH FAST for a single-table aggregate Oracle materialized view , you must have created a materialized view log for the underlying table, or the refresh command will fail. ORGANIZATION INDEX statement where primary key cannot be specified. This could be useful in cases e. CREATE MATERIALIZED VIEW. To fast refresh a materialized join view , you must create a materialized view log for each of the tables referenced by the materialized views. If atomic_refresh is set to FALSE, the indexes are set to UNUSABLE at the beginning and rebuilt after the Complete Refresh.

During the refresh, index statistics are gathere too. A more elegant and efficient way to refresh materialized views is a Fast Refresh. Mviews can be used to replicate a table to another database to prevent users from accessing several databases through database links.

One of the uses of materialized views is replication. You also mentioned using an index , yes, you can create indexes on materialized views. You could just simply index the base tables properly.

It utilizes partitioning and dependencies between the objects to minimize the time it takes to refresh and maintain the data as close to the underlying tables as possible.