The PegaRULES database as initially installed includes 52 tables in a single database instance. Each table stores the persistent objects from one or more concrete classes. The schema (structure and layout) for the database is documented as HTML topics available in the /schema directory of the installation media.
Columns for the table correspond to Single
Value
properties in the object. Some aggregate property
values are stored in a single special column named
pzPVStream, known as the Storage Stream. Binary
values (such as a floating point value, JPG image or DLL file)
are converted to text using Base64 encoding and stored in a
binary large object column (BLOB), known as the Storage
Stream.
A database administrator can view, extend update, and manage the database schema. Certain changes to the database schema must be carefully coordinated with changes to Database and Database Table data instances.
One database instance can support multiple separate Process
Commander systems, using distinct schemas. However, the
prconfig.xml
file of each system must correctly
identify the schema to use.
To identify a schema within a database instance, add the
following line to the prconfig.xml
file after
installation:
<env name="database/baseTable/schema" value="zzzzz" />
where zzzzz is the schema name. See Pega Developer Network article PRKB-23183 Troubleshooting: "Obj-Save is trying to write to a non-existent column".