Hi Amir,
unfortunately i currently have not the time to reply to the initial question,
but adaptive plans do only solve two particular areas at least with
Oracle 12.1: Join methods and PX distribution methods. The adaption also takes
place at first execution only (the statistics collector becomes a
pass-through operation afterwards).
Histograms can still be a issue in case of adaptive plans / adaptive statistics
as they do not apply every time / in every scenario.
Best Regards
Stefan Koehler
Freelance Oracle performance consultant and researcher
Homepage: http://www.soocs.de
Twitter: @OracleSK
"Hameed, Amir" <Amir.Hameed@xxxxxxxxx> hat am 9. November 2015 um 19:32--
geschrieben:
So with the introduction of Adaptive plans and Adaptive Statistics in 12c
where Oracle can (in theory) optimize plans based on the feedback, would
histograms still pose issues? I mean, wouldn’t the optimizer be able to
handle any bad plans through its Adaptive features if it indeed makes a bad
choice in the beginning?
