RE: DML on dual?

John,  

Hmmm, my memory may not be serving me too well here, but this reminds me of something I read in Tom Kyte's newest book. I don't have the book with me, so I can't look it up, but I think he had an example of some sort of home-grown concurrency control mechanism. Probably an example of how not to code. Anyway, I believe the example was such that a session had to hold this lock for the code to proceed. Darn, the one day I don't have that book on hand.  

Cheers,  

David Taft

From: John Darrah [mailto:darrah.john_at_gmail.com]

I've seen several oracle trace files that have the statement "SELECT 1 FROM DUAL FOR UPDATE NOWAIT" I have no idea what the purpose of that statement is but it probably explains what you are seeing.

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