Changes to Database Table instances do not alter the database or its schema.
If you update a Database Table data instance to map an existing table that contains rows to a different class, first move the data from the original table to another table (at a time when Pega Platform is not running). Otherwise, rows from the objects in the new class may overwrite the existing rows.
In a development system (where the production level is 1 or 2), Application Express creates, for each work pool, a new database table (similar in structure to the default table for work items pc_work) and also creates the Database Table data instance that references the new table.The new table is named pc_work_classgroup, where classgroup is the name of the class group.
If this capabilities is not desirable, update the prconfig.xml file or Dynamic System Settings, setting the database/AutoDBSchemaChanges value to "false".
The database/AutoDBSchemaChanges setting must be created first, if it does not already exist, and then set to "false". However, be aware that some functionality requires that this setting be set to "true".
Click Test Connectivity on the Basic tab of a Class form for any concrete class to determine which table and database that Pega Platform uses for instances of that class. This button works for both internal classes — classes mapped to the PegaRULES database — and external classes created by the Connector and Metadata wizard.
To obtain a current record count for a table (identifying Rule-Obj-Class names):
Consult the schema documentation — an HTML file on the Pega Platform installation media — for information on the database schema as it was when your system was installed. To see the current structure and columns of each table, use the Modify Schema wizard.
If a database administrator directly updates a PegaRULES database table while the system is running, you do not need to stop and restart the servers. Open and resave the affected database table data instances to cause users to access the modified table schema. (Resaving is not necessary when you use the Modify Schema wizard to modify the database table schema.)
If your system uses a reports database, be sure to repeat any schema updates made to the PegaRULES database to the affected tables of the reports database.