When Teradata Database is initialized, System Initializer (sysinit) procedures build a default configuration map. The default configuration depends on sysinit options specified by the user, and may include two AMPs or all AMPs in the system. This configuration is stored in both the current and new configuration maps.
When the Teradata Database is operational, Configuration describes the complete system in the new configuration map area.
As the system grows and changes, use Configuration to revise the new configuration map to reflect these types of changes to the system:
- Addition and deletion of vprocs and hosts
- Changes to cluster assignments
- Changes to host assignments
When changing cluster assignments without adding AMPs, make sure that ample disk space is available on all AMPs.
If the system determines that ample space is not available, the system stops. To recover, perform a SYSINIT on the Teradata Database, which results in loss of all data. Teradata recommends that currentperm space should be less than 53% of the total maxperm space before starting a change of clusters without adding AMPs.
After Configuration builds a new configuration map, the Reconfiguration utility redefines the system configuration according to the new map. Reconfiguration copies the new configuration map to the current configuration map.