Working with the PegaRULES database — Schema changes

The schema for the PegaRULES database can grow and evolve through a variety of tools and automatic changes. This topic identifies the types and sources of these changes.

Automatic changes are possible only if the primary account or the administrative account on the Database data instance that defines the connection to the PegaRULES database has the ALTER TABLE and CREATE TABLE capabilities. Often these capabilities are present on development systems but not present on production systems (as determined by the production level value in the System data instance.) In addition, certain capabilities require that the user hold specific privileges.

Initial schema

Pega 7 Platform contains about 106 database tables. This help system summarizes the purpose and contents of each table.

Database table instances define a mapping — typically many to one — between concrete classes and database tables.

Column additions

To support reporting or other operations, it is often useful to "expose" a property value to make it a separate database column. These tools can add a column, or update a column, in an existing database table:

• Property Optimizer
• Modify Schema tool
• Database Class Mapping tool

Optionally, as you create a top-level Single Value property, you can update the associated database table to make this property exposed, by adding a database column, on the New dialog. See Property form — Completing the New/Save As dialog.

Additional tables

In a development system, Pega 7 Platform automatically creates a new table each time you create a new concrete class in these situations. (These tables are created when you create a concrete class indirectly, by using the Application Express, the Connector and Metadata Accelerator, and similar tools. You must hold the SchemaTableCreation privilege.

• Work- — When you define a concrete class derived from Work- that is a class group, Pega 7 Platform creates a new database table that is a copy ("clone") of the pc_work table. The new table is named pc_ZZZZZ_work, where ZZZZZ is the class group name in all lowercase.
• Data- — Optionally, as you use the Data Table wizard (available from the Designer Studio > Data Model > Data Tables > Data Tables landing page) you can save the rows of a data table in a dedicated table. The new table is named pr_zzzzz, where zzzzz is the class name of the table.
  Note: Local data storage replaced data tables.
• History— The new table is named pc_history_ZZZZZ_work, where ZZZZZ is the class group name in all lowercase.

Changes introduced by the Import wizard

Using the Import landing page tab, you can import and apply schema changes from an archive that contains such changes. This approach keeps the schemas of two systems in synch.

Viewing a log of schema changes

Use the Schema Change Tracking tab on the System-Database landing page to review the cumulative schema changes in your system.

To access this tab, select Designer Studio > System > Database > Schema Change Tracking. See System category — System-Database page.

	Column Populator utility, exposed property, Storage Stream
	Property optimization About Database Table data instances
	Atlas — Initial database tables

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