15.00 - HELP INDEX Attributes - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

prodname
Teradata Database
vrm_release
15.00
category
Programming Reference
featnum
B035-1184-015K

HELP INDEX Attributes

The following attributes are reported when you submit a HELP INDEX request.

 

Attribute

Data Type

Description

Unique?

CHARACTER(1)

Defines whether the index is unique or non‑unique.

  • N specifies a non‑unique index.
  • Y specifies a unique index.
  • Primary or Secondary?

    CHARACTER(1)

    Defines whether the index is primary or secondary.

  • P specifies a Primary index.
  • S specifies a Secondary index.
  • This code does not discriminate between USIs and NUSIs: both types of secondary index are reported as S.

    Column Names

    VARCHAR(512)

    Lists the names of the columns defined for the index.

    Note: The system converts each column name, including extended-length names and substitution characters, to its full length. If the constructed list of column names exceeds the maximum length of the Column Names field, the result is truncated after the last comma separator that can fit within the field.

    If the field ends in a comma, the list of names is truncated.

    Index ID

    INTEGER

    System-defined.

    The primary index for a table is always index number 1.

    Secondary indexes are numbered in increments of 4 beginning with index number 4, which is assigned to the first secondary index defined for a table.

    Approximate Count

    FLOAT

    Defines the approximate number of rows in the index subtable.

    Index Name

    CHARACTER(30)

    Lists the index name, if there is one. This column is set to NULL if the index is unnamed.

    See “Column Names” earlier in this table for information about the CHARACTER SET attribute the Teradata Database assigns to INDEX NAME, depending on the language support for your system.

    Ordered or Partitioned?

    CHARACTER(1) CHARACTER SET LATIN

    Defines whether the index is ordered or partitioned.

  • H specifies a hash‑ordered index.
  • P specifies a row‑partitioned index.
  • V specifies a value‑ordered index.
  • CDT Index Type

    CHARACTER(1) CHARACTER SET LATIN

    Defines the type of complex data type NUSI this is.

  • G specifies a a Hilbert R‑tree geospatial NUSI index.
  • N specifies a non‑Hilbert R‑tree geospatial index.