17.10 - EnableTempBLC - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - Database Utilities

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Configuration
Publication ID
B035-1102-171K
Language
English (United States)

Determines whether temperature-based block-level compression (TBBLC) is enabled.

Field Group

Compression

Valid Settings

Setting Description
TRUE TBBLC is enabled. Tables using AUTOTEMP compression (specified in CREATE TABLE or ALTER TABLE statements) will have infrequently accessed data blocks automatically compressed for storage.
In order to use TBBLC, BlockLevelCompression must be set to On.
FALSE TBBLC is disabled. Data blocks are not compressed based on frequency of access.

Default

FALSE

Changes Take Effect

After the DBS Control Record has been written.

Usage Notes

When TBBLC is enabled, AutoCylPackColdData should be set to TRUE, and DisableAutoCylPack should be set to FALSE.

If TBBLC is disabled, tables that are set to use automatic temperature-based compression will behave like tables set to use manual compression until TBBLC is enabled again. The system default for whether tables use manual or automatic compression is set with the DefaultTableMode setting.

BLC enables data compression at the data block (DB) level of the Teradata file system. Compression reduces the amount of storage required for a given amount of data. The BlockLevelCompression field of DBS Control enables and disables BLC.

Data temperature refers to the frequency of access. Hot data is frequently accessed. Cold data is infrequently accessed. Warm data is accessed moderately frequently. TBBLC automatically compresses colder data to save storage space, and decompresses the data if it becomes hotter. At any time, different portions of a table, such as different partitions, may exist in different states of compression depending on their temperatures.

Related Information

For more information on… See…
Block-level compression Teradata Vantage™ - Database Design, B035-1094.
BLOCKCOMPRESSION table attribute Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.
DefaultTableMode field DefaultTableMode.
Ferret COMPRESS, UNCOMPRESS, and FORCE commands Ferret Utility (ferret).
Query bands for compression Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.
Storage group of DBS Control fields Storage Group.