4 Commits

Author	SHA1	Message	Date
Sergei Petrunia	d448cfc92a	MDEV-19134: EXISTS() slower if ORDER BY is defined ... Step #2: "[ORDER BY ...] LIMIT n" should not prevent EXISTS-to-IN conversion, as long as - the LIMIT clause doesn't have OFFSET - the LIMIT is not "LIMIT 0".	2019-05-16 13:03:58 +03:00
Sergei Petrunia	b1f828a82a	MDEV-19134: EXISTS() slower if ORDER BY is defined ... Step 1: Removal of ORDER BY [LIMIT] from the subquery should be done earlier and for broader class of subqueries. The rewrite was done in Item_in_subselect::select_in_like_transformer(), but this had problems: - It didn't cover EXISTS subqueries - It covered IN-subqueries, but was done after the semi-join transformation was considered inapplicable, because ORDER BY was present. Remaining issue: - EXISTS->IN transformation happens before check_and_do_in_subquery_rewrites() is called, so it is still prevented by the present ORDER BY.	2019-05-16 13:03:58 +03:00
Marko Mäkelä	7396dfcca7	Merge 10.2 into 10.3	2018-04-24 20:59:57 +03:00
Michael Widenius	a7abddeffa	Create 'main' test directory and move 't' and 'r' there	2018-03-29 13:59:44 +03:00