17.10 - ROLLBACK SESSION WORKLOAD - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - 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)

The ROLLBACK SESSION WORKLOAD command sets or displays the workload used by rollbacks for a specified host and session.

Syntax

ROLLBACK SESSION host_id, session _id WORKLOAD [ workload_name ] ;

Syntax Elements

host_id, session _id
Identifiers for the host and session for which you want Recovery Manager to display or set the workload for rollbacks.
The session _id maximum is 4294967296.
The session _id must be in the rollback list, that is, at least one of the tables in the output of LIST ROLLBACK TABLES must be from the session specified.
workload_name
Name of the workload to apply to rollback operations in the specified session.
Vantage subsequently executes session rollbacks in the specified workload.
If you do not specify a workload_name, Recovery manager displays the workload name for the current session.

Usage Notes

By default, rollback processing runs in the workload of the current session.

The ROLLBACK SESSION WORKLOAD command allows you to change the priority of the rollback operation. By reducing the priority of less important rollbacks, you can increase the system resource availability for other processes.

This command affects the priority of the rollback process alone. It does not affect the workload or priority of the user session or other session work.

If the DBS Control General field RollbackPriority is set to TRUE, the rollback process runs in the workload of the aborted transaction that is being rolled back. The ROLLBACK SESSION WORKLOAD command can override the DBS Control Rollback Priority field setting, and change the priority of the rollback at any time.

The following usage rules apply to the ROLLBACK SESSION WORKLOAD command:
  • The host_id and the session _id must be in the rollback tables list generated by the LIST ROLLBACK TABLES command from rcvmanager. This indicates that rollback is in progress in that session. You either can display or change the workload.

    If you specify a host_id or a session _id that does not exist in the rollback list, rcvmanager displays an error message, and the command is ignored.

  • If you do not specify a workload_name, the Recovery Manager displays the workload name for the specified host_id and session _id.
  • When you execute the ROLLBACK SESSION WORKLOAD command, an event is logged, even if the specified workload is the same as the current session workload. If you specify an invalid workload_name, no event is logged.

    The following example displays the event log entry after successful execution of the rcvmanager command.

    > ROLLBACK SESSION 52, 1664 WORKLOAD WD-Rollback-Workload;
    ROLLBACK SESSION WORKLOAD command completed successfully.
    02/01/31 15:34:28 Rollback WORKLOAD for 52, 1664 changed to WD-Rollback-Workload;
    it was WD-Medium.