Question - What is Transient Journaling in Teradata?
Answer -
The transient journal is a system-maintained dictionary table that provides a way to protect transactions from various system failures and from deadlock (see SQL Request and Transaction Processing 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.