15.00 - SHOWCOMPRESS - Teradata Database

Teradata Database Utilities

Product
Teradata Database
Release Number
15.00
Content Type
Configuration
Publication ID
B035-1102-015K
Language
English (United States)
Last Update
2018-09-25

SHOWCOMPRESS

Purpose  

Lists subtables that have block-level compressed data blocks.

Syntax  

Usage Notes  

SHOWCOMPRESS lists all tables that have data compressed at the data block level, regardless of the way compression was specified for the tables. For more information on the amount of a table that is block-level compressed, use the “SHOWBLOCKS” command.

Block-level compression (BLC) compresses table data at the File System level to save storage space. BLC can be manually performed for individual tables and table partitions using the “COMPRESS” command, or by using the BLOCKCOMPRESSION query band when data is loaded into empty tables.

Temperature-based block-level compression (TBBLC) automatically compresses infrequently accessed (“cold”) table data in the background. TBBLC can be specified at table creation time using the BLOCKCOMPRESSION option to CREATE TABLE and ALTER TABLE, or as a default for all tables by using controls in the Compression and Storage groups of DBS Control settings.

SHOWCOMPRESS checks only the PERMANENT area, even if the scope is set to encompass a wider class of objects.

Related Topics

 

For more information on…

See…

Block-level compression

Database Administration.

BLOCKCOMPRESSION table attribute, CREATE TABLE, ALTER TABLE statements

SQL Data Definition Language.

Query bands for BLC and TBBLC

SQL Data Definition Language.

Compression and Storage groups of settings in DBS Control

Chapter 11: “DBS Control (dbscontrol).”