Cubes Property Sheet: Materialized View tab

Cube materialized views are cubes that have been enhanced with the capabilities of materialized views:

Refresh: The database refresh system monitors the master tables (that is, the source tables for the dimensional objects) and refreshes the cube when the materialized views display old data.
Rewrite: The database query rewrite system redirects queries for summary data from the master tables to the materialized views.

You can create materialized views just for refresh, or for both refresh and rewrite.

Enable Materialized View Refresh of the Cube

Select this option to refresh of the data in the cube automatically by using the database materialized view refresh system. This method of refreshing a cube is an alternative to a manual refresh. You can enable and disable refresh without losing the other settings.

Refresh Method

Choose one of the following refresh methods:

Fast: Performs an incremental refresh based on changes to the data in the relational source.
Complete: Performs a complete refresh of all the data in the cube.
Force: Performs a fast refresh if possible, and otherwise, a complete refresh.

Refresh Mode

Choose one of the following refresh modes:

On Demand: Waits for you to initiate a refresh manually.
On Commit: Initiates a fast refresh whenever the database commits a transaction that changes the source table.
Start/Next: Uses the expressions displayed in the Start With and Next Refresh boxes to schedule refreshes.

Start With:

Displays the expression for scheduling the first refresh using the Start/Next method. Typically, this expression identifies a single date and time for the initial refresh.

Next Refresh:

Displays the expression for scheduling the additional refreshes using the Start/Next refresh mode. Typically, this expression identifies an interval for scheduling routine periodic refreshes.

Modify

Displays the Set Refresh Times dialog box for setting the Start With and Next Refresh expressions.

Constraints

Controls the types of constraints that are used during a refresh:

Trusted: Use both enforced or unenforced constraints.
Enforced: Use only enforced constraints.

Enable the Query Rewrite Materialized View

Controls whether the materialized views are used by query rewrite. Select this box to submit the materialized views to the query rewrite system. You can enable and disable query rewrite without losing the other settings.

The Refresh and Rewrite tabs display status information about the materialized views.

Refresh: Displays information about the status of automatic refresh.
- Compatibility Check List: Identifies the types of checks made for materialized views and the result of the tests. The related objects may have characteristics that are incompatible with the creation of a materialized view.
  - Status: The success or failure of the object to pass the checks.
  - Object: Lists the cubes, measures, and master dimension tables involved in a refresh.
  - Check: The criteria for creating a refresh materialized view.
- Materialized View Details: Describes the materialized view as currently defined.
  - Name: Lists characteristics of a refresh materialized view.
  - Value: Identifies the value or current status of each characteristic
Rewrite: Displays information about the status of query rewrite. The Rewrite tab displays the same type of reports as Refresh, but the details are different.

Relational Schema Advisor

Evaluates the master tables for the constraints needed to get the maximum use from the materialized views, particularly for query rewrite. The Advisorl looks for NOT NULL constraints, primary key constraints, foreign key constraints, and materialized view logs on the master fact tables. It generates a script that you can save to a file and run at your convenience to apply these changes. Any changes that cannot be implemented because of existing conditions are commented out of the script.

Cubes Property Sheet: Materialized View tab

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