Detecting SELECT FOR UPDATE WAIT ... failures

List,

We have a packaged app. One of our processes is issuing 'SELECT X FROM TABLE_Y WHERE A=:1 FOR UPDATE WAIT 10' (names changed to protect the vendor....). .

This process is periodically having problems because the 'SELECT FOR UPDATE' is timing out. This happens a few times a day, at unpredictable times. (Yes, I know the code should cope gracefully with this......... but it doesn't).

I've been asked - what other process is holding the lock that this process is failing to get?

The vendor is saying that they can't spot the conflicting DML in their code. A trace file doesn't seems to help. I can't spot 'SELECT FOR UPDATE' in Logminer output.

Do you have any thoughts on how I can approach this, aside from querying the lock views all day?

Stuart

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