Sparse Join Indexes - Advanced SQL Engine - Teradata Database

Database Introduction

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
17.00
Published
June 2020
Language
English (United States)
Last Update
2021-01-23
dita:mapPath
qia1556235689628.ditamap
dita:ditavalPath
lze1555437562152.ditaval
dita:id
B035-1091
lifecycle
previous
Product Category
Teradata Vantageā„¢

Indexes include a subset of the columns of one or more tables. Typically, indexes include the column values from all rows in the table. Sparse join indexes further limit the index to include only a subset of the table rows, in addition to a subset of table columns. Sparse JIs can include one or more tables, and can also be aggregate JIs.

If queries frequently are limited to a subset of the rows of a table, for example, rows with a specific value in one column, a sparse JI that includes only those rows can improve performance by providing a more limited data set to be queried.