Initiates immediate, high-priority migrations necessary to move cylinders modified by the FORCE command to appropriate classes of storage. Normal migration is a background process with a lower priority.
Optimization can cause extremely heavy loads on system resources, and have a negative impact on system performance. If BEGIN OPTIMIZE is used on a production system, it should be used only during scheduled maintenance windows.
Migrations resulting from BEGIN OPTIMIZE occur at the maximum possible speed, without regard to potential impacts to existing workloads. Because cylinders marked HOT or COLD using the FORCE command are at the maximum temperature extremes, these cylinders are likely to be the first selected for migration, depending on available space.
If space on storage media of appropriate performance grade is not available, some cylinders are moved out of FAST and SLOW storage locations to make room for the HOT and COLD table data, respectively.
Example: BEGIN OPTIMIZE
Ferret ==> > begin optimize BEGIN OPTIMIZE command could consume significant system resources Do you wish to continue?? (Y/N) > Y Optimization has been started on all vprocs If you wish to revert this optimization to a low level background mode, you can issue a CANCEL OPTIMIZE command