Author: Michael Widenius <monty@mariadb.org>

Date:   Sun May 15 15:46:29 2022 +0300

    greedy_search() and best_extension_by_limited_search() scrambled table order

    best_extension_by_limited_search() assumes that tables should be sorted

    according to size to be able to quickly disregard bad plans. However the

    current usage of swap_variables() will change the table order to a not

@@ -596,8 +596,8 @@ limit 10;

 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra

 1	PRIMARY	nation	ALL	PRIMARY	NULL	NULL	NULL	25	4.00	Using where; Using temporary; Using filesort

 1	PRIMARY	supplier	ref	PRIMARY,i_s_nationkey	i_s_nationkey	5	dbt3_s001.nation.n_nationkey	1	100.00	

-1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	7.03	Using where

-1	PRIMARY	partsupp	eq_ref	PRIMARY,i_ps_partkey,i_ps_suppkey	PRIMARY	8	dbt3_s001.part.p_partkey,dbt3_s001.supplier.s_suppkey	1	100.00	Using where; FirstMatch(supplier)

+1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	7.03	Using where; Start temporary; Using join buffer (flat, BNL join)

+1	PRIMARY	partsupp	eq_ref	PRIMARY,i_ps_partkey,i_ps_suppkey	PRIMARY	8	dbt3_s001.part.p_partkey,dbt3_s001.supplier.s_suppkey	1	100.00	Using where; End temporary

-1  PRIMARY	part	... Using where

+1  PRIMARY	part	... Using where; Start temporary; Using join buffer (flat, BNL join)

-1  PRIMARY	partsupp ... Using where; FirstMatch(supplier)

+1  PRIMARY	partsupp ... Using where; End temporary