Repository tier
The repository tier consists of the metadata repository and, if installed, other data stores to support other product modules. The metadata repository contains the shared metadata, data, and configuration information for InfoSphere® Information Server product modules. The other data stores store extended data for use by the product modules they support, such as the operations database, which is a data store that is used by the engine operations console.
The repository tier includes the metadata repository database for IBM® InfoSphere Information Server. The metadata repository exists as its own schema in this database. The metadata repository is a shared component that stores design-time, runtime, glossary, and other metadata for product modules in the InfoSphere Information Server suite.
The repository tier also includes other data stores. Some of these data stores might be referred to as databases or repositories throughout the documentation, based on legacy naming conventions. However, they might exist as either separate database schemas in a shared database or as schemas in their own separate databases in the product suite. Some of these data stores can exist on other computers, and in that sense the repository tier can be thought of as a logical tier. However, when this documentation refers to the repository tier computer, it is the computer that hosts the database for the metadata repository. Location and connection information for the other data stores in the repository tier is stored in the metadata repository.
The repository tier can include these data stores:
- As part of IBM InfoSphere Metadata Asset Manager, a data store called the staging area is installed as a separate schema in the database for the metadata repository.
- If InfoSphere Information Analyzer is installed, the repository tier also includes one or more analysis databases, one per project, for example, which are installed as distinct databases outside of the metadata repository database. The analysis databases are used by InfoSphere Information Analyzer when it runs analysis jobs.
- An operations database can be installed with IBM InfoSphere DataStage® and QualityStage® as a separate schema in the metadata repository database or as a separate schema in another database. Additional operations databases can be created, one per InfoSphere Information Server engine, if desired.
- A data store called the Standardization Rules Designer database is installed with Standardization Rules Designer. By default, it is installed as a separate schema in the metadata repository database. However, you can choose to install it in a separate schema in another existing database.
- A data store called the exceptions database is installed after the Data Quality Exception Console installed. By default, it is installed as a separate schema in the metadata repository database. However, you can choose to install it in a separate schema in another existing database.
The services tier must have access to the metadata repository. When product modules store or retrieve metadata, services on the services tier connect to the metadata repository and manage the access to the databases from the product modules.
The engine tier and the client tier must have direct access to the analysis databases and operations databases, which are part of the repository tier.
The following diagram shows some of the components that make up the repository tier.
