16.10 - Configuration Maps and Reconfiguration - Teradata Database

Teradata Database Support Utilities

Teradata Database
June 2017

The Configuration utility describes the complete Teradata Database system in the new configuration map area.

As the Teradata Database system grows and changes, use Configuration to revise the new configuration map to reflect the following types of changes to the Teradata Database system:

  • Addition and deletion of vprocs and hosts
  • Changes to cluster assignments

Use the configuration maps to perform these tasks:

  • Store the identification and status of each vproc in the Teradata Database system
  • Identify the AMPs that comprise each AMP cluster
  • Identify each PE and its associated host

The Teradata Database system contains two types of configuration maps:

  • Current configuration maps describe the current arrangement and status of vprocs in the Teradata Database system. There is one current configuration map for each contiguous map in the system.
  • The new configuration map includes changes and additions to the configuration, which are implemented by the Reconfiguration utility.

The new configuration map serves as input to the Reconfiguration utility.

Typically, Reconfiguration is used to alter the number of AMPs in a Teradata Database system. The new configuration map includes the status of each AMP in a Teradata Database system.

After Configuration builds a new configuration map, Reconfiguration redefines the Teradata Database system configuration according to the new map. Reconfiguration copies the new configuration map to the current configuration map on each node.

Every table is assigned a data distribution map when the table is created or altered. These maps determine the AMPs to which the table rows are distributed. If AMPs are added or deleted, or if cluster assignments are changed in the new configuration, tables can be assigned to new maps, and the rows of these tables must be redistributed among the AMPs in the new distribution maps. If the table was assigned to have fallback, the new distribution maps determine which AMPs receive the fallback copies of the rows.

Because row redistribution can be a slow process, especially for large tables, and the system must be offline when the Reconfiguration utility runs, you should use the utility to change distribution maps and redistribute rows from as few tables as possible. Instead, you should either manually use ALTER TABLE MAP statements to reassign the tables to new maps and start row redistribution, or use the Advisor and Mover tool procedures to have map changes and data redistribution happen as a background process when the system is back online after running the Reconfiguration utility.
  • For more information about ALTER TABLE MAP, see SQL Data Definition Language - Syntax and Examples.
  • For more information about the Advisor and Mover procedures, see Database Administrationand SQL Functions, Operators, Expressions, and Predicates.
  • For more information about running the Advisor and Mover tools from Viewpoint, see Teradata Viewpoint User Guide.