The FME Server Core uses a database to store job and repository information. The FME Server database should never be edited directly, although querying the database for job history and other statistical information is common.
FME Server provides a PostgreSQL database server with an Express installation. Certain Distributed/Fault Tolerant installation scenarios also allow the option of installing the PostgreSQL database server provided with the installer. Otherwise, you must provide your own database server. PostgreSQL, Oracle, and SQL Server are supported.