
9-48 IBM Informix OnLine Database Server Administrator’s Guide
Two-Phase Commit and Logical Log Records
Heuristic Rollback Records
Figure 9-11 illustrates the writing sequence of the logical log records during
a heuristic rollback. (Refer to page 9-36 for a description of a heuristic
rollback.) Since a heuristic rollback only occurs after the participant sends a
message that itcan commit,and the coordinator sendsa message tocommit,
the first phase of this protocol is the same as that shown in Figure 9-10. In
Figure 9-11,the heuristic rollbackisassumed to be theconsequenceof a long-
transactionconditionthatoccursattheParticipantOne(P1)OnLinedatabase
server. Only the interactions between thecoordinator and the P1 participant
are shown.
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