Database schema

The database schema for the Decision Center repository is provided to help you understand how the repository operates.

Note:

IBM® supports use of the database schema to aid viewing or reporting from the repository, but documented changes to the schema in future releases of Decision Center might require corresponding changes to any SQL you use to view or report from the repository. IBM does not support use of SQL to modify directly the contents of the repository.

The database tables are generated automatically according to the rule model.

Some of the database columns are used to implement some features of the rule model. For example, all rule model project elements contain a PROJECT column, which is a reference to the RULEPROJECT table. Aggregated elements are not project elements and therefore do not define that column. However, they all have a CONTAINER column that is a reference to the project element to which they are linked.

All enumerations from the rule model are stored in the database in the same way:

  • A column to store the values

  • A column to indicate whether or not the value is still in use (deprecated or not)

When a value is removed from an enumeration, it becomes deprecated. This means that existing instances that use this value can still refer to it, but new data cannot use it.

The scripts that create the tables are generated by Ant tasks.

Tables for extended features

Decision Center automatically creates tables to store extended features.

Decision Center creates new tables for new aggregated elements, while added features for existing base classes are stored in a sibling table.

For example, two database tables exist for the ruleArtifact class:
RULEARTIFACT
Stores the basic features of the class.
RULEARTIFACTSIBLING
Stores the extended features of the class.

Some classes can be derived from the ruleArtifact class and define features that are not defined in the basic class. Instances of the basic class populate the RULEARTIFACTSIBLING table with null values, and instances of the derived class use these columns.

View descriptions

Some views are automatically created with the database tables to simplify queries on the schema.

Views are defined from the model for the following classes:
  • AbstractQuery
  • BOM
  • BOM2XOMMapping
  • Deployment
  • Operation
  • Resource
  • Event
  • RuleArtifact
  • Ruleflow
  • RulePackage
  • ScenarioSuite
  • Template
  • VariableSet
  • Vocabulary
You can use two kinds of views:

  • The standard/extended view, which aggregates data from standard and sibling tables by using a basic join

  • The details view, which aggregates data from standard and sibling tables, and adds versioning data

A third view for aggregations is used internally and is not documented.