Shared Memory

Shared memory is a working memory jointly used by multiple processes of a database instance.

The DBM server of a database instance can consist of multiple processes. These processes communicate via the shared memory. This communication is necessary to:

0     Coordinate access to shared resources, such as the parameter file or the log file of the DBM server.

0     Transfer database parameters.

0     Retrieve the results of special DBM server processes, such as the command scheduler.

The database system also saves the content of the DBM server's shared memory in the dbmsrv_<database_name>.shm and dbmsrv_<database_name>.shi files in the directory <independent_data_path>\wrk. In this way, the contents of the shared memory are also available even when no DBM server processes are active.

DBM server processes from different database instances cannot communicate with one another via the shared memory.

See also:

Database Manager CLI, Further Commands for the Database Manager Settings