17.10 - Other Forms of Compression Used by Vantage - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Detailed Topics

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1184-171K
Language
English (United States)

Hash and Join Index Row Compression

When describing compression of hash and join indexes, compression refers to a logical row compression in which multiple sets of non-repeating column values are appended to a single set of repeating column values. This enables the system to store the repeating value set only once, while any non-repeating column values are stored as logical segmental extensions of the base repeating set.

Block-Level Compression

Block-level compression, or BLC, is a lossless physical compression method that can be specified in a CREATE TABLE statement. Block-level compression can be applied to row-level security constraint columns, which are not eligible for multivalue compression and algorithmic compression.

For information about BLC and how the system applies compression to various types of tables, see Teradata Vantage™ - Database Utilities, B035-1102.

Autocompression for Column-Partitioned Tables

When describing system-selected autocompression of containers in column-partitioned tables, compression refers to various compression methods that Vantage can use to compress the column values of a container.