Storage Group Setting | Tuning Teradata Virtual Storage | Teradata Vantage - 17.00 - 17.05 - Storage Group - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - Teradata® Virtual Storage

Product
Advanced SQL Engine
Teradata Database
Release Number
17.00
17.05
Release Date
June 2020
Content Type
Configuration
Publication ID
B035-1179-170K
Language
English (United States)

Purpose

Each field in the Storage group specifies the initial temperature that will be assigned to data loaded or inserted into empty subtables of a particular type. The temperature represents the expected frequency of access to that data, and can determine whether the data is compressed, and where the data is stored.

Because the frequency of access is continually monitored by Vantage, the temperature can change over time from the initial temperature setting.

The individual Storage setting names and defaults are listed below.

Storage Field Default Temperature
DEPOT Temperature HOT
GLOBAL TEMP Fallback Temperature WARM
GLOBAL TEMP Fallback CLOB Temperature WARM
GLOBAL TEMP Primary Temperature WARM
GLOBAL TEMP Primary CLOB Temperature WARM
PERMANENT JOURNAL Temperature HOT
PERM Fallback Temperature WARM
PERM Fallback CLOB Temperature WARM
PERM Primary Temperature

The Parallel Upgrade Tool (PUT) sets the default for PERM primary data based on the system configuration. For some configurations the default is HOT.

WARM
PERM Primary CLOB Temperature WARM
SPOOL Temperature HOT
WAL Temperature HOT
All Other Temperature

Controls initial data temperature set for data loaded into empty subtables that are not specifically controlled by other Storage group fields.

WARM

Valid Settings

Setting Description
HOT Data is expected to be accessed frequently.
WARM Data is expected to be accessed moderately frequently.
COLD Data is expected to be accessed infrequently.
DEFAULT Uses the default temperature for this type of data. Resets the field to the Teradata default value for the specified table or data type.

Changes Take Effect

After the DBS Control record has been written.

Usage Notes

The Storage field settings are honored when data is loaded into empty tables by any of the following techniques:
  • INSERT/INSERT ... SELECT statement
  • CREATE TABLE AS ... WITH DATA statement
  • CREATE JI statement
  • Load utilities TPump, FastLoad, MultiLoad, Teradata Parallel Transporter
  • Table Rebuild utility
The TVSTemperature query bands and the Ferret FORCE command override these storage settings.

Because data temperature is assigned at the cylinder level, after initial assignment, data in different partitions of a partitioned table can have different temperatures.

Data can be moved (migrated) automatically to faster or slower grades of storage as data temperatures change due to changing data access patterns.