Use Pin Shared Memory (-pinshm) to prevent the database engine from swapping shared memory contents to disk, which can help improve performance.

Operating system and syntax UNIX 
-pinshm
Use with Maximum value Minimum value Single-user default Multi-user default
DBS 1 0 – 0

The Pin Shared Memory (-pinshm) parameter does not have any arguments. Set -pinshm as follows to indicate the status of Pin Shared Memory:

  • 0 — Shared Memory may not be locked. This is the default.
  • 1 — Shared Memory is to be locked.

The Pin Shared Memory (-pinshm) parameter may be modified while your database is online using PROMON or through the _DbParams VST. This change will only take effect on the primary broker and any newly spawned servers. Online changes to existing secondary brokers will require a restart.

Notes

  • Pin Shared Memory (-pinshm) is only supported on UNIX platforms, excluding IBM AIX.
  • On Solaris, the effective user requires sys_conf privileges. For _progres, the effective user requiring sys_conf privileges is the real user, regardless of the setuid or setgid on the executable. For server processes, the effective user requiring sys_conf privileges is the setuid user when set or the real user if no setuid.

You can use this parameter to support continuous operation of the database. For more information, see Change database parameters while the database is running.