Purpose
Recovers Teradata Database systems or tables that are in Out of Service, Interrupted, or Read Only state.
Syntax
SYSTEM RECOVER <tdpid> [, <tdpid>, ...] [REASON '<reason>']Parameters
- tdpid
- Unique identifier (TDPID) of a Teradata Database system.
- REASON
- Reason for clearing. Use quotation marks when the reason is more than one word.
Usage Considerations
All Unity managed tables for the specified tdpid(s) change to RESTORE state and go through recovery.
If the table cannot recover successfully due to a transient error, then the table remains in Interrupted state, which raises an alert. After resolving the error, retry the recovery.
If Unity cannot successfully recover the table due to data consistency issues, then the table enters Unrecoverable state.
The command operation replays the Recovery Log to bring the Teradata Database server from Out of Service, Interrupted, or Read Only state to Active state without requiring manual intervention to restore the data. If the recovery operation is unsuccessful, the Teradata Database system or table becomes Interrupted or Unrecoverable based on the error returned.
Running this operation on a Teradata Database system places each table in that Teradata Database system from Out of Service or Interrupted into Restore state. The system completes recovery within a short period while tables on the system continue recovery at an individual level. As each table completes recovery successfully, it becomes Active and accessible for client transactions.
Example
The following example demonstrates system level recovery after running SYSTEM FREEZE.
unityadmin> system freeze bltor;
Operation Number : 4
Operation Name : Freezing Systems
User : admin
User Name : Main Administration User
Start Time : 10/19 12:34:06
Systems:
[1] bltor
Updates:
10/19 12:34:08 [-] Info: Freezing selected systems
10/19 12:34:08 [-] Info: Successfully froze 1 systems
10/19 12:34:08 [-] Info: Operation finished
Status : Finished (1)
Finish Time : 10/19 12:34:08
Systems:
[1] bltor - Finished (1)
unityadmin> system recover bltor;
Operation Number : 5
Operation Name : Recovering Systems
User : admin
User Name : Main Administration User
Start Time : 10/19 12:34:38
Systems:
[1] bltor
Updates:
10/19 12:34:38 [-] Info: Recovering selected systems
10/19 12:34:38 [-] Info: Successfully started recovery on 1 systems
10/19 12:34:38 [-] Info: Operation finished
Status : Finished (1)
Finish Time : 10/19 12:34:38
Systems:
[1] bltor - Finished (1)