16.20 - Transient Journaling - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Detailed Topics

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Release Date
March 2019
Content Type
Programming Reference
Publication ID
B035-1184-162K
Language
English (United States)

The transient journal is a system-maintained dictionary table that provides a way to protect transactions from various system failures and from deadlock (see Teradata Vantage™ SQL Request and Transaction Processing, B035-1142 for a description of deadlock). Each transaction processed by Teradata Database records a before change image of rows that are touched by the transaction. Then if a transaction fails for some reason, the before change image of any modified rows can be retrieved from the transient journal and written over the modifications, returning the row to the same state it was in before the transaction occurred. Teradata Database removes all before change images from the transient journal after a transaction commits.