15.00 - TempBLCIOThresh - 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

TempBLCIOThresh

Purpose  

Specifies the maximum threshold number of outstanding I/O operations that can exist on a node above which the background temperature-based block-level compression (TBBLC) task pauses for a short period before running again. If the system remains busy, the process waits according to the interval defined by “TempBLCInterval”.

This setting is effective only when TBBLC is enabled.

Field Group

Compression

Valid Range

1 through 1,000

Default

1

Changes Take Effect

After the DBS Control Record has been written.

Usage Notes

This setting limits the impact of TBBLC on foreground workloads.

BLC enables data compression at the data block (DB) level of the Teradata Database 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 Topics

 

For more information on…

See…

Block-Level Compression

Database Administration.

BLOCKCOMPRESSION table attribute

SQL Data Definition Language.

Enabling TBBLC

“EnableTempBLC”.

Ferret COMPRESS, UNCOMPRESS, and FORCE commands

Chapter 13: “Ferret Utility (ferret).”

Query bands for compression

SQL Data Definition Language.

Storage group of DBS Control settings

“Storage Group”.