Reply To: F_JT044C: Warning: HVR encountered change to table ‘mytable’ in transaction id 0xXX but it did not see the corresponding ‘begin transaction’ record

Simon Faas

HVR capture has the concept of expiring transactions.

This can happen for 2 reasons

1) the transaction is open for more than 3 hours and it has no changes to replicated tables inside, it will be silently expired

2) the transaction is open for more than 3 days it will be expired even it if it has replicated transactions inside. But in this case a warning will be issued.

This “expiring of transaction” has been implemented to avoid capture going back too far after a restart ( HVR’s capture will go back to the oldest open transaction after a restart, which may cause high latency).

The most likely reason for the warning that you got is that we had a transaction that was expiring due to reason 1 and then a change to a replicated table came in. HVR had already expired the begin transaction record and will give a warning. But it will replicate the change nevertheless.

Note: The timeouts for 1 and 2 can be modified using environment variables. But I would recommend against that. I think the default values are fine.

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