Example: NOWAIT Option - Analytics Database - Teradata Vantage

SQL Data Manipulation Language

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2024-04-05
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lifecycle
latest
Product Category
Teradata Vantage™

You have a request that you do not want to be placed in the lock queue if it cannot be serviced immediately. Use the NOWAIT option. For example:

     LOCKING employee FOR READ NOWAIT
     SELECT employee_number,  last_name
     FROM employee
     WHERE department_number=401;

Result:

     *** Failure 7423 Object already locked and NOWAIT.
            Transaction Aborted. Statement# 1, Info =0

Another request had employee locked, so you must resubmit the request.

     LOCKING employee FOR READ NOWAIT
     SELECT employee_number, last_name
     FROM employee
     WHERE department_number=401;

Result:

      *** Query completed. 7 rows found. 2 columns returned.
      *** Total elapsed time was 1 second.
     employee_number  last_name
     ---------------  --------------------
                1003  Trader
                1004  Johnson
                1013  Phillips
                1002  Brown
                1010  Rogers
                1022  Machado
                1001  Hoover

This time, no locks were being held on employee, so the request completed successfully.