Adaptive Query Optimization
From: Charlotte Hammond <charlottejanehammond_at_yahoo.com>
Date: Mon, 23 Mar 2015 16:54:19 +0000
Message-ID: <535955829.1130480.1427129659222.JavaMail.yahoo_at_mail.yahoo.com>
Hi All,I'm reading about Adaptive Query Optimization in 12c and I'm a bit confused about the interplay of Adaptive Plans and Adaptive Statistics. I would greatly appreciate any explanation on this.... When does Adaptive Statistics (Cardinality Feedback) come into play in 12c in this context? Won't a plan based on bad cardinality estimates have already been "fixed" at run-time during the first execution by the Adaptive Plan functionality? When would it need to be subsequently re-optimized using Adaptive Statistics? Many thanks!Charlotte
Date: Mon, 23 Mar 2015 16:54:19 +0000
Message-ID: <535955829.1130480.1427129659222.JavaMail.yahoo_at_mail.yahoo.com>
Hi All,I'm reading about Adaptive Query Optimization in 12c and I'm a bit confused about the interplay of Adaptive Plans and Adaptive Statistics. I would greatly appreciate any explanation on this.... When does Adaptive Statistics (Cardinality Feedback) come into play in 12c in this context? Won't a plan based on bad cardinality estimates have already been "fixed" at run-time during the first execution by the Adaptive Plan functionality? When would it need to be subsequently re-optimized using Adaptive Statistics? Many thanks!Charlotte
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Mar 23 2015 - 17:54:19 CET