Locks and Concurrency - Advanced SQL Engine - Teradata Database

SQL Data Definition Language Detailed Topics

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Published
July 2021
Language
English (United States)
Last Update
2021-07-27
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B035-1184
lifecycle
previous
Product Category
Teradata Vantage™

When you do not specify the SPOOL, TEMPORARY, or PERM options, MODIFY USER places an ACCESS lock on the database being altered to run concurrently with all DML requests.

Specifying the SPOOL, TEMPORARY, and PERM options require an EXCLUSIVE lock.

This statement also places a rowhash WRITE lock on the database for DBC.DBase. The SPOOL, TEMPORARY, and PERM options then place a second lock on the immediate parent for DBC.DBase. For PERM, the second lock is a rowhash-level WRITE lock. For SPOOL or TEMPORARY, the second lock is a rowhash-level READ lock.

The SPOOL, TEMPORARY, and PERM options also place a rowhash-level WRITE lock on DBC.DataBaseSpace. The PERM option then places a second rowhash-level WRITE lock on the immediate parent for DBC.DataBaseSpace.