A Single Value property that is visible as a column in a database table is said to be exposed. Aggregate properties, properties within an embedded page, and properties that are not exposed are contained in a specially formatted Storage Stream or BLOB column. Most PegaRULES database tables contain a Storage Stream column named pzPVStream.

Which properties are exposed affects the record selection operations in list view and summary view rules. In many cases, your database administrator can cause a property previously stored only inside the Storage Stream column to become a separate exposed column.

Only top-level Single Value properties can be exposed. If your application needs a column corresponding to an embedded property values, the values can be copied to the top level or exposed indirectly through instances of an Index- class.

Don't confuse an exposed property with an indexed database column. For example, the property Work-.pyID is an exposed property in the table pc_work. However, if this table contains several million work objects, a list view search for a .pyID value of "W-135" causes an expensive database table scan. Creating database indexes or Process Commander declarative indexes can speed database operations in such situations. PEPEN 9/15/06 CLINIC Ask your database administrator to create database indexes. Use the Declarative Index wizard to create a Declare Index rule and index class.

Exposing too many properties in a table may speed reporting and searching operations, but make insert and update operations slower. The tradeoff and relative impact depends on hardware and software; no general guidelines exist.

	aggregate property, Column Populator utility, index, schema, Storage Stream
	About the Modify Database Schema wizard How to expose a property in a column About the Declarative Index wizard How to monitor Storage Stream operations Working with the PegaRULES database

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