15.00 - Fallback With Hash Indexes - Teradata Database

Teradata Database Design

prodname
Teradata Database
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

Fallback With Hash Indexes

You can define fallback for hash indexes. The criteria for deciding whether to define a hash index with fallback are similar to those used for deciding whether to define fallback on base tables.

If you do not define fallback for a hash index and an AMP is down, then the following additional factors become critical.

  • The hash index cannot be used by the Optimizer to solve any queries that it covers.
  • The base tables on which the hash index is defined cannot be updated.