17.00 - Prevent Mid-transaction Throttle Delays - Teradata Workload Management

Teradata Vantageā„¢ - Workload Management User Guide

prodname
Advanced SQL Engine
Teradata Workload Management
vrm_release
17.00
created_date
June 2020
category
Administration
User Guide
featnum
B035-1197-170K

The Do not delay queries within transactions that are holding locks higher than 'access' option on the Other tab of the General view overrides throttle limits when a request is part of a transaction that holds a lock higher than access level. Like the Blocker options, this option prevents a request in the delay queue from holding locks needed by active requests.

This option applies to all request throttles. Because it exempts certain requests from throttles, this option can cause the number of concurrent requests to exceed the throttle limit. Evaluate how use of this option affects your site. The TDWM Statistics API returns the number of active requests that are running solely due to this option. In addition, the following DBQLogTbl columns can help you to assess the impact of this feature on throttle limits.

DBQLogTbl Field Description
LockLevel The highest-level lock obtained when the request ran. This lock is from a previous request in the transaction.
ThrottleBypassed Indicates if this request ran solely due to the Prevent Mid-transaction Throttle Delays option. This flag is not set if running the request did not override the throttle limit.
TnxUniq Used in conjunction with the userid and procid to uniquely identify the transaction under which this request ran.