15.10 - BEGIN OPTIMIZE - Teradata Database

Teradata Database Teradata Virtual Storage

Teradata Database

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.

Note: BEGIN OPTIMIZE initiates optimization on all nodes and all tables of the system, not just the tables on which the FORCE command was recently used.

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.

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
  • “CANCEL OPTIMIZE” on page 25
  • “FORCE” on page 26
  • “SHOWCYLALLOC” on page 16