16.20 - In-Doubt Resolution - Teradata Tools and Utilities

Teradata® Call-Level Interface Version 2 Reference for Mainframe-Attached Systems

Teradata Tools and Utilities
September 2019
Programming Reference

If there is a site or communication failure (for example, a power failure, operating system error, or telecommunication failure) during the process just described, there are different recovery actions, depending on the step at which the failure occurred.

If the failure occurs at this point in the Two-phase commit process... Then the participant...
before step 4 rolls back the updates.
during step 6 after the participant has received and logged the coordinator’s commit request, the participant continues with the commit process.
after step 4, but before step 6

is said to be in-doubt as to whether it should commit or roll back the updates, so it cannot take any unilateral action.

The participant must wait for in-doubt resolution to complete the transaction.

There are two forms of in-doubt resolution: automatic and manual. They are explained later in further detail.