Typically, the only time a CREATE IMAGE command is required is after a restart.

On restarting the system, CREATE [SYSTEM] IMAGE attempts to restore the Kognitio to a consistent state. This includes recreating any potentially inconsistent RAID parity areas, completing any pending RECLAIM , and rolling back any incomplete transactions.

Kognitio’s Memory image re-use means CREATE IMAGE is only required if

  • there has been a change to persistent memory version in the software

  • a node has been restarted or a container was lsot so the RAM images have been lost.




CREATE IMAGE restores RAM images that were present before the restart, as dictated by the information in the System Tables. Therefore all table and view images that were present when Kognitio was last up, are reloaded. Contents held in RAM ONLY tables <data-ram-only> are lost.

CREATE SYSTEM IMAGE loads the minimal amount into RAM for a working system, and updates the System tables to reflect this.

In all situations, the System tables are loaded into RAM from disk. On receiving a CREATE SYSTEM IMAGE command, all user tables are marked as being on disk and all view images and compressed data maps are dropped.