SYSTEM HALT Command | unityadmin | Teradata Unity - SYSTEM HALT - Continuous Availability - Teradata Unity

Teradata® Unity™ User Guide

Continuous Availability
Teradata Unity
Release Number
September 2020
English (United States)
Last Update
Product Category
Analytical Ecosystem


Changes a table or Teradata Database system in the Active state to the Out-of-Service state.

If a multi-table write runs, and a table is in Out of Service or Interrupted state, then all associated tables in the write automatically become Out of Service or Interrupted.


SYSTEM HALT tdpid | tdpid [ON database.tablename[,tdpid,...]];


Name of a database and table currently in the Unity Data Dictionary. The table name that you specify must be fully qualified.
Unique identifier (TDPID) of a Teradata Database system.

Usage Considerations

If making a state change for a table on all the Teradata Database systems, the table has same data across all Teradata Database systems when this operation completes.

When running this command, Unity holds any new transactions/statements until all in-flight transactions close for the object. RecoveryCheckpointTimeout determines the duration of wait time. If in-flight transactions are not closed within this time limit, the operation aborts, an error displays, and the state returns to the state prior to the attempt.

When making the state change to the Teradata Database system, all tables Unity manages on that Teradata Database system become Out of Service.

If applied to the Teradata Database system successfully, all tables in the Teradata Database system become Out of Service. If this operation is applied to a Teradata Database system, all tables must be Active, else the operation results in an error, and no action takes place.


The following example shows using SYSTEM HALT to place a table t4_cp_tpp from a Teradata Database cp_tpp004u in Out of Service state. The administrator then runs OPERATION CHECK to confirm operation completion.

unityadmin>  system halt cp_tpp004u.t4_cp_tpp; 
The request is currently processing as operation number 2.
You may check its status using the command 'operation check 2'.
unityadmin> operation check 2;
Operation Number : 2
Operation Name   : Halting Table
User             : admin
User Name        : Main Administration User
Progress (%)     : 100
Status           : Finished (1)
Start Time       : 01/08 13:13:33
Finish Time      : 01/08 13:13:36
    [1] bltor - Finished (1)
    [2] fast - Finished (1)
    01/08 13:13:36 [-] Info: Halting table cp_tpp004u.t4_cp_tpp
    01/08 13:13:36 [-] Info: Requesting mgmt X lock on 'cp_tpp004u.t4_cp_tpp'
    01/08 13:13:36 [-] Info: Mgmt X lock on 'cp_tpp004u.t4_cp_tpp' granted
    01/08 13:13:36 [-] Info: Releasing mgmt X lock on 'cp_tpp004u.t4_cp_tpp'
    01/08 13:13:36 [-] Info: Successfully halted table on 2 systems
    01/08 13:13:36 [-] Info: Operation finished