Update matching_candidates_in_table() to treat all conditions similar

Fixed also that the 'with_found_constraint parameter' to
matching_candidates_in_table() is as documented: It is now true only
if there is a reference to a previous table in the WHERE condition for
the current examined table (as it was originally documented)

Changes in test results:
- Filtered was 25% smaller for some queries (expected).
- Some join order changed (probably because the tables had very few rows).
- Some more table scans, probably because there would be fewer returned
  rows.
- Some tests exposes a bug that if there is more filtered rows, then the
  cost for table scan will be higher. This will be fixed in a later commit.

1 files changed, 4 insertions, 4 deletions

diff --git a/mysql-test/main/join_cache.result b/mysql-test/main/join_cache.result
index 938167035a2..1e649c193b6 100644
--- a/mysql-test/main/join_cache.result
+++ b/mysql-test/main/join_cache.result
@@ -3071,11 +3071,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.metaid	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 1	SIMPLE	t7	ref	PRIMARY	PRIMARY	4	test.t1.metaid	1	Using index
 1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	4	test.t7.artistid	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	SIMPLE	t3	ref	t3_metaid,t3_formatid,t3_metaidformatid	t3_metaidformatid	4	test.t1.metaid	1	Using index condition; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
-1	SIMPLE	t4	eq_ref	PRIMARY,t4_formatclassid,t4_formats_idx	PRIMARY	4	test.t3.formatid	1	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 1	SIMPLE	t9	index	PRIMARY,t9_subgenreid,t9_metaid	PRIMARY	8	NULL	2	Using where; Using index; Using join buffer (incremental, BNL join)
 1	SIMPLE	t10	eq_ref	PRIMARY,t10_genreid	PRIMARY	4	test.t9.subgenreid	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 1	SIMPLE	t11	eq_ref	PRIMARY	PRIMARY	4	test.t10.genreid	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t3	ref	t3_metaid,t3_formatid,t3_metaidformatid	t3_metaidformatid	4	test.t1.metaid	1	Using index condition; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t4	eq_ref	PRIMARY,t4_formatclassid,t4_formats_idx	PRIMARY	4	test.t3.formatid	1	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 SELECT t1.uniquekey, t1.xml AS affiliateXml,
 t8.name AS artistName, t8.artistid, 
 t11.name AS genreName, t11.genreid, t11.priority AS genrePriority,
@@ -4507,8 +4507,8 @@ SET SESSION join_buffer_size = 256;
 EXPLAIN
 SELECT t1.a, t2.c FROM t1,t2 WHERE t1.a=t2.a AND t2.b=99;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	idx	NULL	NULL	NULL	15	Using where
-1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t2.a	36	Using where; Using join buffer (flat, BNLH join)
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	36	
+1	SIMPLE	t2	ALL	idx	NULL	NULL	NULL	15	Using where; Using join buffer (flat, BNL join)
 SELECT t1.a, t2.c FROM t1,t2 WHERE t1.a=t2.a AND t2.b=99;
 a	c
 SET SESSION join_cache_level=@save_join_cache_level;