Property optimization

The values of all aggregate properties and some Single Value properties are stored in a BLOB column (the Storage Stream), usually in a compressed form. These properties cannot be retrieved for reports and can slow retrieval and processing in other operations. You can significantly improve reporting and searching performance by optimizing, that is exposing, Single Value properties as distinct columns, however, it might slow insert and update operations. The tradeoff and relative impact depends on your hardware and software.

You can expose a property even after the property has values. You will then need to copy values from the BLOB into the new column using the Database Column Populator.

Use the following tools to optimize and populate newly optimized columns. Some tools perform the same functionality, so choose the tool and the property optimization method that best meets your needs.

• Property Optimization Tool — Accessed from the Designer Studio, exposes columns and populates them with values. It is available on development systems and is appropriate for ad-hoc changes when you only have a few Single Value, top-level properties to expose. For aggregate and embedded property values, this feature provides an alternative to the Declarative Index wizard.
• Database Column Populator Utility — Command-line utility that populates columns on a system by communicating directly with the database. A running instance of the Pega 7 Platform is not required.
• Service-enabled Column Populator Utility - Command-line utility that populates columns on a system by communicating with a REST service. A running instance of the Pega 7 Platform is required.
• Modify Schema Wizard — Accessed from the Designer Studio, exposes columns but does not populate them. You can also view schema, increase the size of columns, and generate an SQL text file that defines a table that can be used later to modify the schema. Used to review the current database table structure, understand class-to-database table mapping, and provide additional context.

You can use the Database Class Mappings page along with the Advanced tab on the Property form to help you identify properties that might need to be exposed that are not currently exposed. The Column Inclusion field on the Property form contains a value of blank, Optional, Required, or Requested that indicates the opinion of the developer who created or updated the property as to whether this property might need to be exposed. This value does not affect any runtime behavior of the property. However, using the Database Class Mappings page, you can compare the values in this field with the current schema. To identify properties marked as Required that are not exposed. Select Designer Studio> Data Model > Classes and Properties > Database Class Mappings to access this page.

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