Logical-log records written during a heuristic rollback

The following figure illustrates the sequence in which the database server writes the logical-log records during a heuristic rollback. Because a heuristic rollback only occurs after the participant sends a message that it can commit and the coordinator sends a message to commit, the first phase of this protocol is the same as that shown in Figure 1. When a heuristic rollback occurs, the rollback is assumed to be the consequence of a long-transaction condition that occurs at the Participant 1 (P1) database server. The end result is a transaction that is inconsistently implemented. See The heuristic rollback scenario.
Figure 1. Logical-log records written during a heuristic rollback
This figure shows how logical-log records are written during a heuristic rollback. The paragraph that precedes this figure describes the content of the figure.

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