LOCK SYSTEM

Use the LOCK SYSTEM statement to obtain a global session to prevent access to Kognitio by sessions other than the current one. You can only do this if there are no other active connections to Kognitio - if other sessions are running, you receive an error message.

Usage

LOCK SYSTEM

Notes

The LOCK SYSTEM command is normally reserved for the exclusive use of the System Administrator but this can be changed. (To use the command, you need the CREATE SYSTEM IMAGE privilege, which permits you to lock the system.)

Global sessions are compulsory when updating certain system tables, for example, IPE_USER.

After a user issues a LOCK SYSTEM command and obtains a global session, any attempt to access Kognitio by another session receives the error message:

Sessions inhibited

The user who obtains the global session holds it until he/she logs off. That is, they must issue

  • A DISCONNECT, or

  • An implicit disconnect by reconnecting to Kognitio.

There is no “unlock” command. For more information on locks see Monitoring Locks.

See RECLAIM on how to use a global lock prior to reclaiming disk space.