Can you index a materialized view?

A materialized view can be partitioned, and you can define a materialized view on a partitioned table. You can also define one or more indexes on the materialized view. Unlike indexes, materialized views can be accessed directly using a SELECT statement.

How do I view materialized view logs?

all_mview_logs will show you all the materialized view logs that you have access to. user_mview_logs will show you all the materialized view logs that you own.

How do I create a materialized view log?

Oracle Database creates the materialized view log in the schema of its master table. You cannot create a materialized view log for a table in the schema of the user SYS . Specify the name of the master table for which the materialized view log is to be created.

What’s the purpose of a materialized view log?

A materialized view log can capture the primary keys, row IDs, or object identifiers of rows that have been updated in the master table. The standard naming convention for a materialized view log table is: MLOG$_.

What is the difference between a view and a materialized view?

A view uses a query to pull data from the underlying tables. A materialized view is a table on disk that contains the result set of a query. Materialized views are primarily used to increase application performance when it isn’t feasible or desirable to use a standard view with indexes applied to it.

What is Materialised log?

Materialized view log is a table associated with the master table of a materialized view. When changes are made to master table data, Oracle Database stores those changes description in the materialized view log and then uses the materialized view log to refresh materialized views based on the master table.

Why use materialized view instead of a table?

Materialized views are basically used to increase query performance since it contains results of a query. They should be used for reporting instead of a table for a faster execution.

What is fast refresh in materialized view?

Fast refresh for a materialized view containing joins and aggregates is possible after any type of DML to the base tables (direct load or conventional INSERT , UPDATE , or DELETE ). It can be defined to be refreshed ON COMMIT or ON DEMAND .

How to REFRESH MATERIALIZED VIEW in Oracle?

Oracle provides flexible ways to refresh materialized views: you can refresh them full or incremental; you can refresh them on demand or at the commit time in the source table. When the size of the materialized view grows, one needs to explore ways to perform the refresh faster. One of the ways to expedite the refresh is to use parallel execution.

How do I create an index in Oracle?

Creating Oracle Indexes Once you have decided you need to create an index you use the create index command. The command is pretty straightforward as seen in this example: CREATE INDEX ix_emp_01 This statement creates an index called IX_EMP_01. This index is built on the DEPTNO column of the EMP table.

What is Index view?

An indexed view is a view that has been materialized or stored in the database. The index that is created on the view is stored and updated by the database engine as the underlying table is updated. Indexed views work great for situations where your result set returns a lot of rows and needs to be aggregated.