Restrictions on Hash Indexes - Teradata Database

Teradata Database Design

Product
Teradata Database
Release Number
15.10
Language
English (United States)
Last Update
2018-10-06
Product Category
Software

Restrictions on Hash Indexes

The following restrictions apply to all hash indexes.

  • Excluding the primary index, you can define a maximum of 32 indexes on a table.
  • Each multicolumn NUSI that specifies an ORDER BY clause counts as 2 consecutive indexes in this calculation.

    These 32 indexes can be any combination of secondary, hash, and join indexes, including the system‑defined secondary indexes used to implement PRIMARY KEY and UNIQUE constraints.

    You cannot define hash indexes for global temporary trace tables, for NoPI tables, or for column‑partitioned tables. See “NoPI Tables, Column‑Partitioned NoPI Tables, and Column-Partitioned NoPI Join Indexes” on page 230), CREATE GLOBAL TEMPORARY TRACE TABLE, “CREATE HASH INDEX,” and “CREATE TABLE” in SQL Data Definition Language Detailed Topics.

  • You cannot define a partitioned hash index.
  • You cannot define a hash index with a primary AMP index or no primary index.
  • You cannot include columns having XML, BLOB, CLOB, Period, ARRAY, VARRAY, or JSON data types in any hash index definition.