PostgreSQL is used for various things in a dCache system: The SRM, the pin manager, the space manager, the replica manager, the billing, and the pnfs server might make use of one or more databases in a single or several separate PostgreSQL servers.

The SRM, the pin manager, the space manager and the replica manager will use the PostgreSQL database as configured at cell start-up in the corresponding batch files. The billing will only write the accounting information into a database if it is configured with the option -useSQL. The pnfs server will use a PostgreSQL server if the pnfs-posgresql version is used. It will use several databases in the PostgreSQL server.