- Use sparse maps for small tables. Continue to use the Reconfiguration utility (Reconfig) to redistribute tables after a system expansion.
- Use sparse maps for small tables. Use Teradata Database MAPS architecture instead of Reconfig to redistribute tables after a system expansion.
About Choosing Not To Use Teradata Database MAPS Architecture
Sites that do not use Teradata Database MAPS architecture should not specify a default map for a database, user, or profile. If you do specify a default, you will have to change it after you add AMPs to the system.
When you run the Configuration (Config) and Reconfiguration (Reconfig) utilities to add AMPs, DBAs need to take the following actions:
- If you are using Config, define TD_Map2, which is a contiguous map that includes all the AMPs in the system plus the added AMPs. If this is not the first system reconfiguration, name this map TD_Mapn where n is between 1 and 63 and is a currently unused map name.
- If you are using Reconfig, choose the options to move both Data Dictionary tables and all user tables.
- After Reconfig moves all user tables to TD_Map2, drop the previous map, TD_Map1, using a DROP MAP request to prevent accidental use of this old map.
For more information on Config and Reconfig, see Support Utilities.
About Using Only the Sparse Maps for Small Tables Capability
Some sites may choose to use sparse maps for small tables while continuing to use Reconfig to move tables to a new configuration. In this case, after enabling MAPS and running DIPMAPS, either one or two system default sparse maps are created, depending on the number of nodes in the system. You can then query the TableToSparseMapSizingV(X) view to identify small tables and their suggested map sizes.