- You must drop and rebuild value-ordered join indexes and value-ordered hash indexes before they can be used again.
- If you converted NoPI or PA tables to PI tables before the reconfiguration, they can be converted back.
- You can run the CheckTable utility and the SCANDISK command of the Ferret utility on any or all tables.
- After a reconfiguration that changes the number of AMPs, you should run the DIPMAPS DIP script. This creates two new system sparse maps that are appropriate to the new configuration. Consider moving tables that use previous system sparse maps to the new sparse maps. For more information on the DIP utility, see Utilities.
- If the new configuration includes additional AMPs, and you have allowed Reconfiguration to assign the new contiguous map to the existing user tables that used contiguous maps, Teradata recommends that you drop the obsolete contiguous map. This will assure that tables are distributed among all AMPs in the new configuration and will help prevent users from using the older map. Using the older, smaller contiguous map accidentally can potentially introduce skew to the system, because the rows of tables using the older map will not be distributed to all AMPs in the new configuration.
When you perform a reconfiguration as a result of expanding system storage space, Reconfig offers to divide the new space in a prorated fashion among existing users and databases. (Alternatively all the new space is allocated to user DBC.) If you chose to divide the space among users and databases, after the underlying tables have been analyzed for map usage and altered as recommended, you can use the AdjustSpace procedure to adjust the per-AMP space and skew settings.
For more information about AdjustSpace and other procedures associated with Teradata Database MAPS Architecture, see SQL Functions, Operators, Expressions, and Predicates.