Product Environment 9-35
Heuristic Decisions: What and Why
Figure9-9
Characteristics of Heuristic “End-Transaction”
When it occurs: A heuristic end-transaction occurs after the participant
OnLine sends a “can commit” message for a piece of
work.
Why it occurs: Administrator executed.
tbmode -Zaddress, terminating the piece of work being
performed on behalf of the global transaction.
What occurs: This piece of work is rolled back and ended at this
OnLine database server, independent of coordinator
instructions.
Shared memory: Shared-memory resources are released. Transaction
entry is removed from the transaction table.
Logical log files: All records associated with the piece of work areclosed.
Files containing these records can be freed, if all other
conditions are met.
Logical log: ENDTRANSlogical log record is written. ROLLWORK log
record is written if it does not already exist.
Coordinator: The lack of a transaction entry in shared memory is
interpretedby the coordinator to mean that the piece of
work has committed.
OnLine messages: “Transaction completed abnormally (endtx)” is written
in the participant OnLine message log.