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You are here		chandlerdba.com SQL Patch, and a Parallel mistake - Neil Chandler's DB Blog
\|	\|	jonathanlewis.wordpress.com Push Group by \| Oracle Scratchpad	6.8 parsecs away Travel
\|	\|	Jump to summary. A new optimizer feature that appears in 23c (probably not 21c) was the ability to push group by clauses into union all set operations. This will happen unhinted, but can be hinted with the highly memorable [no_]push_gby_into_union_all() hint that appeared in 23.1.0.0 according to v$sql_hint. and the feature can be disabled by...	6.8 parsecs away Travel
\|	\|	antognini.ch Partition-Wise Operations - New Features in 12c and 18c - Striving for Optimal Performance	7.3 parsecs away Travel
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\|	\|	dioncho.wordpress.com Interesting case of the restriction of global hints \| Dion Cho - Oracle Performance Storyteller	8.3 parsecs away Travel
\|	\|	One of my colleagues sent following test case, of which he couldn't control the join order with hints. 1. Create objects - table t1, t2 and t3 2. Now Let's set the join order as T1->T2->T3, using global hints convention. But it seems that Oracle does not work as expected. It really seems that the...	8.3 parsecs away Travel
\|	\|	dban00b.wordpress.com Latch free waits, Dynamic Statistics, and the Result Cache - DBA n00b	61.5 parsecs away Travel
\|		2016-11-29 EDIT: Oracle has announced that in 12.2 the features that drove this overuse of the result cache (dynamic stats triggered by SPDs) will default to off, and provided patches to apply to 12.1 as well. More info here. Also, some investigation by Mauro Pagano around the impact of the new OPTIMIZER_ADAPTIVE_STATISTICS parameter turned up...	61.5 parsecs away Travel