16.10 - Changing States with unityadmin - Teradata Unity

Teradata Unity User Guide

Product
Teradata Unity
Release Number
16.10
Published
January 2018
Language
English (United States)
Last Update
2018-03-29
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Teradata Database State Changes

You can change the state of Teradata Databases with unityadmin. The Teradata Database system state must be Active, Standby, or Read Only to start sessions on the Teradata Database system. The following table shows how to change Teradata Database accessibility and change Unity states.
From To Commands
Active Standby SYSTEM DEMOTE
Standby Active SYSTEM PROMOTE

To Active State Commands

The following table describes how to place a Teradata Database system or table in Active state from another state.
To Active from Commands
Out of Service SYSTEM RECOVER
Standby SYSTEM PROMOTE
Read Only SYSTEM RECOVER
If a table is in a Restore state, it automatically goes into an Active state when recovery is complete.

From Active State Commands

From Active state, a Teradata Database system or table can be placed into the following states.
From Active to Commands
Unrecoverable SYSTEM DEACTIVATE
Out of Service SYSTEM HALT
Read Only SYSTEM FREEZE
Standby SYSTEM DEMOTE
From an Active state, a system is automatically placed in Restore state if the queue of pending Write requests is greater than the RecoveryQueueLimit parameter. This prevents the system from getting reads directed to it when it is far behind in writes, allowing the system time to catch up with the other systems in the cluster.