Pin Shared Memory (-pinshm)

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.