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From Bryan Pendleton <bpendleton.de...@gmail.com>
Subject Re: XPLAIN and statement recompilation (invalidation)
Date Thu, 14 Oct 2010 01:46:53 GMT
> The result of the above event is that an entry for the query is added
 > twice to SYSXPLAIN_STATEMENTS; once when the recompilation
> of the query is triggered, and once when the query has completed.

This surprises me. I don't understand why re-compilation of the query
is getting all the way to the execution phase; I would have expected
the compilation to be performed without ever opening and closing
execution-phase result sets.

I think it would be great if you could log this and even better if
we could come up with a simple and predictable test case that demonstrates
it, as it sounds like the index statistics technique is somewhat
unpredictable.

This is a very interesting finding, and thanks for tracking
it down and raising it!

bryan

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