Repository Architecture

Repository Architecture

The PowerCenter repository resides in a relational database. The repository database tables contain the instructions required to extract, transform, and load data. Repository clients access the repository database tables through the Repository Service. A repository client is any PowerCenter component that connects to the repository.

The Repository Service manages repository metadata transaction requests from repository clients. Each Repository Service manages a single repository. The Repository Service uses object-locking to ensure the consistency of metadata in the repository.

A Repository Service process is a multi-threaded process that fetches, inserts, and updates metadata in the repository database tables. A Repository Service process is an instance of the Repository Service that runs on a particular machine, or node.

The Repository Service accepts client metadata transaction requests from the following PowerCenter components:

PowerCenter Client tools. Use the Designer to create and store mapping metadata in the repository. Use the Workflow Manager to store workflow metadata and connection object information in the repository. Use the Workflow Monitor to retrieve workflow run status information and session logs written by the Integration Service. Use the Repository Manager to organize and secure metadata by creating folders. You can manage the repository from the PowerCenter Administration Console.

pmrep and infacmd. Use pmrep to perform repository metadata administration tasks, such as listing repository objects. Use infacmd to perform service-related functions, such as creating or removing a Repository Service.

Integration Service. When you start the Integration Service, it connects to the repository to schedule workflows. When you run a workflow, the Integration Service retrieves workflow task and mapping metadata from the repository. During the workflow run, the Integration Service writes workflow status information to the repository.