15.00 - DeadlockTimeOut - Teradata Database

Teradata Database Utilities

Product
Teradata Database
Release Number
15.00
Content Type
Configuration
Publication ID
B035-1102-015K
Language
English (United States)
Last Update
2018-09-25

DeadlockTimeOut

Purpose  

Used by the Dispatcher to determine the interval (in seconds) between deadlock timeout detection cycles. The value in DeadLockTimeout specifies the time-out value for requests that are locking each other out on different AMPs. When the system detects a deadlock, it aborts one of the jobs.

Pseudo table locks reduce deadlock situations for all-AMP requests that require write or exclusive locks. However, deadlocks still may be an issue on large systems with heavy concurrent usage. In batch operations, concurrent requests may contend for locks on Data Dictionary tables.

Field Group

General

Valid Range

10 though 3600 seconds

Default

240 seconds

Changes Take Effect

After the next Teradata Database restart.

Recommendation

Reduce the value in this field to cause more frequent retries with less time in a deadlock state.

Faster CPUs significantly reduce the system overhead for performing deadlock checks, so you can set the value much lower than the current default of 240 seconds. The following general recommendations apply.

 

IF your applications…

THEN you should…

incur some dictionary deadlocks

set the value to between 30 and 45 seconds.

incur few dictionary deadlocks

retain the default value of 240 seconds.

incur many true deadlocks

set the value as low as 10 seconds.

are predominantly Online Transaction Processing (tactical) applications

set the value as low as 10 seconds.