Chapter 12 DBMS-Specific Features

Materialized view logs

When DML changes are made to master table data, Oracle Database stores rows describing those changes in the materialized view log and then uses the materialized view log to refresh materialized views based on the master table.

Materialized view logs are supported for Oracle 11g and higher. PowerDesigner models materialized view logs as extended objects with a stereotype of <<Materialized view log>>.

Creating a materialized view log

You can create a materialized view log as follows:

Materialized view log properties

You can modify an object's properties from its property sheet. To open a materialized view log property sheet, double-click its Browser entry or click the Properties button on its parent table Oracle tab.

The General tab displays the master table name and the comment. The following properties are available on the Partitions tab:

Name Description
Type Specifies the method for paritioning the table. You can choose between:

  • Range/Composite - Partitions the table on ranges of values from the column list.
  • Hash - Partitions the table using the hash method.
  • List - Partitions the table on lists of literal values from column.
  • Reference - Equipartitions the table being created (the child table) by a referential constraint to an existing partitioned table (the parent table).
  • System - Partitions the table by the partitions specified.


When you select a type, additional options are displayed, to allow you to specify the appropriate parameters.

 

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