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.
The individual Storage setting names and defaults are listed in this table.
| 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
- INSERT/INSERT … SELECT statement
- CREATE TABLE AS … WITH DATA statement
- CREATE JI statement
- Load utilities TPump, FastLoad, MultiLoad, Teradata Parallel Transporter
- Table Rebuild utility
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.