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About DAC Repository Objects

All DAC repository objects are associated with a source system container. For more information about source system containers, see About Source System Containers and About Object Ownership in the DAC.

The DAC repository stores application objects in a hierarchical framework that defines a data warehouse application. The DAC allows you to view the repository application objects based on the source system container you specify. The source system container holds the metadata that corresponds to the source system with which you are working.

A data warehouse application comprises the following repository objects:

• Subject area. A logical grouping of tables related to a particular subject or application context, as well as the tasks that are associated with the tables. Subject areas are assigned to execution plans, which can be scheduled for full or incremental loads. A subject area also includes the tasks required to load the subject area tables.
• Tables. Physical database tables defined in the database schema. Can be transactional database tables or data warehouse tables. Table types can be fact, dimension, hierarchy, aggregate, and so on, as well as flat files that can be sources or targets.
• Task. A unit of work for loading one or more tables. A task comprises the following: source and target tables, phase, execution type, truncate properties, and commands for full or incremental loads. When you assemble a subject area, the DAC automatically assigns tasks to it. Tasks that are automatically assigned to the subject area by the DAC are indicated by the Autogenerated flag in the Tasks child tab of the Subject Areas tab.
• Task Groups. A group of tasks that you define because you want to impose a specific order of execution. A task group is considered to be a "special task."
• Execution plan. A data transformation plan defined on subject areas that needs to be transformed at certain frequencies of time. An execution plan is defined based on business requirements for when the data warehouse needs to be loaded. An execution plan comprises the following: ordered tasks, indices, tags, parameters, source system folders, and phases.
• Schedule. A schedule specifies when and how often an execution plan runs. An execution plan can be scheduled for different frequencies or recurrences by defining multiple schedules.