Return >= 1 from matching_candidates_in_table if records > 0.0

Having rows >= 1.0 helps ensure that when we calculate total rows of joins
the number of resulting rows will not be less after the join.

Changes in test cases:
- Join order change for some tables with few records
- 'Filtered' is much higher for tables with few rows, as 1 row is a high
  procent of a table with few rows.

mysql-test/main/join_nested_jcl6.result

@@ -2120,9 +2120,9 @@ FROM t5 LEFT JOIN
 ON (t5.b=t8.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	
-1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (incremental, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 1	SIMPLE	t7	const	PRIMARY	PRIMARY	4	const	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
 SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
 FROM t5 LEFT JOIN                
 (t6 LEFT JOIN t7 ON t7.a=1, t8)
@@ -2137,9 +2137,9 @@ FROM t5 LEFT JOIN
 ON (t5.b=t8.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	
-1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (incremental, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 1	SIMPLE	t7	ref	b_i	b_i	5	const	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
 SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
 FROM t5 LEFT JOIN                
 (t6 LEFT JOIN t7 ON t7.b=2, t8)

mysql-test/main/opt_trace.result

@@ -9823,7 +9823,7 @@ test.t1	analyze	status	Engine-independent statistics collected
 test.t1	analyze	status	OK
 EXPLAIN EXTENDED SELECT * from t1 WHERE a between 1 and 5 and b <= 5;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	100	0.25	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	100	1.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where `test`.`t1`.`a` between 1 and 5 and `test`.`t1`.`b` <= 5
 select JSON_DETAILED(JSON_EXTRACT(trace, '$**.selectivity_for_columns')) from INFORMATION_SCHEMA.OPTIMIZER_TRACE;

mysql-test/main/opt_trace_selectivity.result

@@ -160,16 +160,16 @@ JSON_DETAILED(JSON_EXTRACT(trace, '$**.considered_execution_plans'))
                             },
                             {
                                 "access_type": "index_merge",
-                                "resulting_rows": 0.6,
-                                "cost": 2.172957403,
+                                "resulting_rows": 1,
+                                "cost": 2.092957403,
                                 "chosen": true
                             }
                         ],
                         "chosen_access_method": 
                         {
                             "type": "index_merge",
-                            "records": 0.6,
-                            "cost": 2.172957403,
+                            "records": 1,
+                            "cost": 2.092957403,
                             "uses_join_buffering": false
                         }
                     }
@@ -180,7 +180,7 @@ JSON_DETAILED(JSON_EXTRACT(trace, '$**.considered_execution_plans'))
             "plan_prefix": 
             [],
             "table": "t1",
-            "rows_for_plan": 0.6,
+            "rows_for_plan": 1,
             "cost_for_plan": 2.292957403
         }
     ]

mysql-test/main/range.result

@@ -2765,7 +2765,7 @@ EXPLAIN
             "selectivity_pct": 6.730769231
           },
           "rows": 7,
-          "filtered": 6.730769157,
+          "filtered": 14.28571415,
           "index_condition": "t2.d is not null",
           "attached_condition": "(t2.d,t2.e) in (<cache>((4,4)),<cache>((7,7)),<cache>((8,8))) and octet_length(t2.f) = 1"
         }

mysql-test/main/range_mrr_icp.result

@@ -2749,7 +2749,7 @@ EXPLAIN
           "key_length": "5",
           "used_key_parts": ["d"],
           "rows": 7,
-          "filtered": 6.730769157,
+          "filtered": 14.28571415,
           "index_condition": "t2.d is not null",
           "attached_condition": "(t2.d,t2.e) in (<cache>((4,4)),<cache>((7,7)),<cache>((8,8))) and octet_length(t2.f) = 1",
           "mrr_type": "Rowid-ordered scan"

mysql-test/main/rowid_filter.result

@@ -1316,7 +1316,7 @@ EXPLAIN
           "key_length": "4",
           "used_key_parts": ["l_receiptDATE"],
           "rows": 18,
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
         }
@@ -1345,7 +1345,7 @@ l_shipdate BETWEEN '1996-10-01' AND '1996-10-10' AND
 l_receiptdate BETWEEN '1996-10-05' AND '1996-10-10' AND
 o_totalprice BETWEEN 200000 AND 250000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	0.57	38.89	Using index condition; Using where
+1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	5.56	38.89	Using index condition; Using where
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_totalprice	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	1.00	7.47	14.29	Using where
 set statement optimizer_switch='rowid_filter=on' for ANALYZE FORMAT=JSON SELECT l_shipdate, l_receiptdate, o_totalprice
 FROM orders, lineitem
@@ -1382,7 +1382,7 @@ ANALYZE
           "r_rows": 18,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "r_filtered": 38.88888889,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
@@ -1453,7 +1453,7 @@ EXPLAIN
           "key_length": "4",
           "used_key_parts": ["l_receiptDATE"],
           "rows": 18,
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
         }
@@ -1482,7 +1482,7 @@ l_shipdate BETWEEN '1996-10-01' AND '1996-10-10' AND
 l_receiptdate BETWEEN '1996-10-05' AND '1996-10-10' AND
 o_totalprice BETWEEN 200000 AND 250000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	0.57	38.89	Using index condition; Using where
+1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	5.56	38.89	Using index condition; Using where
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_totalprice	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	1.00	7.47	14.29	Using where
 set statement optimizer_switch='rowid_filter=off' for ANALYZE FORMAT=JSON SELECT l_shipdate, l_receiptdate, o_totalprice
 FROM orders, lineitem
@@ -1519,7 +1519,7 @@ ANALYZE
           "r_rows": 18,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "r_filtered": 38.88888889,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
@@ -2505,7 +2505,7 @@ ANALYZE
           "r_rows": 1,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 49.20000076,
+          "filtered": 100,
           "r_filtered": 100,
           "index_condition": "t1.nm like '500%'",
           "attached_condition": "t1.fl2 = 0"
@@ -2558,7 +2558,7 @@ ANALYZE
           "r_rows": 1,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 49.20000076,
+          "filtered": 100,
           "r_filtered": 100,
           "index_condition": "t1.nm like '500%'",
           "attached_condition": "t1.fl2 = 0"

mysql-test/main/rowid_filter_innodb.result

@@ -1306,7 +1306,7 @@ EXPLAIN
           "key_length": "4",
           "used_key_parts": ["l_receiptDATE"],
           "rows": 18,
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
         }
@@ -1335,7 +1335,7 @@ l_shipdate BETWEEN '1996-10-01' AND '1996-10-10' AND
 l_receiptdate BETWEEN '1996-10-05' AND '1996-10-10' AND
 o_totalprice BETWEEN 200000 AND 250000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	0.57	38.89	Using index condition; Using where
+1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	5.56	38.89	Using index condition; Using where
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_totalprice	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	1.00	5.67	14.29	Using where
 set statement optimizer_switch='rowid_filter=on' for ANALYZE FORMAT=JSON SELECT l_shipdate, l_receiptdate, o_totalprice
 FROM orders, lineitem
@@ -1372,7 +1372,7 @@ ANALYZE
           "r_rows": 18,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "r_filtered": 38.88888889,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
@@ -1443,7 +1443,7 @@ EXPLAIN
           "key_length": "4",
           "used_key_parts": ["l_receiptDATE"],
           "rows": 18,
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
         }
@@ -1472,7 +1472,7 @@ l_shipdate BETWEEN '1996-10-01' AND '1996-10-10' AND
 l_receiptdate BETWEEN '1996-10-05' AND '1996-10-10' AND
 o_totalprice BETWEEN 200000 AND 250000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	0.57	38.89	Using index condition; Using where
+1	SIMPLE	lineitem	range	PRIMARY,i_l_shipdate,i_l_receiptdate,i_l_orderkey,i_l_orderkey_quantity	i_l_receiptdate	4	NULL	18	18.00	5.56	38.89	Using index condition; Using where
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_totalprice	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	1.00	5.67	14.29	Using where
 set statement optimizer_switch='rowid_filter=off' for ANALYZE FORMAT=JSON SELECT l_shipdate, l_receiptdate, o_totalprice
 FROM orders, lineitem
@@ -1509,7 +1509,7 @@ ANALYZE
           "r_rows": 18,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 0.566194832,
+          "filtered": 5.555555344,
           "r_filtered": 38.88888889,
           "index_condition": "lineitem.l_receiptDATE between '1996-10-05' and '1996-10-10'",
           "attached_condition": "lineitem.l_shipDATE between '1996-10-01' and '1996-10-10'"
@@ -2495,7 +2495,7 @@ ANALYZE
           "r_rows": 1,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 49.20000076,
+          "filtered": 100,
           "r_filtered": 100,
           "index_condition": "t1.nm like '500%'",
           "attached_condition": "t1.fl2 = 0"
@@ -2548,7 +2548,7 @@ ANALYZE
           "r_rows": 1,
           "r_table_time_ms": "REPLACED",
           "r_other_time_ms": "REPLACED",
-          "filtered": 49.20000076,
+          "filtered": 100,
           "r_filtered": 100,
           "index_condition": "t1.nm like '500%'",
           "attached_condition": "t1.fl2 = 0"
@@ -2967,8 +2967,8 @@ id	y	x
 1	2	1
 explain extended select * from t1 join t2 on t1.id = t2.x where t2.y = 2 and t1.id = 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	const	PRIMARY	PRIMARY	4	const	1	100.00	Using index
-1	SIMPLE	t2	index_merge	x,y	y,x	5,5	NULL	1	100.00	Using intersect(y,x); Using where; Using index
+1	SIMPLE	t1	const	PRIMARY	PRIMARY	4	const	1	#	Using index
+1	SIMPLE	t2	index_merge	x,y	y,x	5,5	NULL	1	#	Using intersect(y,x); Using where; Using index
 Warnings:
 Note	1003	select 1 AS `id`,`test`.`t2`.`y` AS `y`,`test`.`t2`.`x` AS `x` from `test`.`t1` join `test`.`t2` where `test`.`t2`.`y` = 2 and `test`.`t2`.`x` = 1
 drop table t1, t2;

mysql-test/main/rowid_filter_innodb.test

@@ -70,6 +70,7 @@ let $q=
 select * from t1 join t2 on t1.id = t2.x where t2.y = 2 and t1.id = 1;
 
 eval $q;
+--replace_column 10 #
 eval explain extended $q;
 
 drop table t1, t2;

mysql-test/main/selectivity.result

@@ -72,18 +72,18 @@ and r_name = 'ASIA'
 order by
 s_acctbal desc, n_name, s_name, p_partkey;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	0.31	Using where; Using temporary; Using filesort
+1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	0.50	Using where; Using temporary; Using filesort
+1	PRIMARY	region	ALL	PRIMARY	NULL	NULL	NULL	5	20.00	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	partsupp	ref	PRIMARY,i_ps_partkey,i_ps_suppkey	i_ps_partkey	4	dbt3_s001.part.p_partkey	3	100.00	Using where
 1	PRIMARY	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.partsupp.ps_suppkey	1	100.00	Using where
 1	PRIMARY	nation	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	100.00	Using where
-1	PRIMARY	region	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.nation.n_regionkey	1	20.00	Using where
 2	DEPENDENT SUBQUERY	region	ALL	PRIMARY	NULL	NULL	NULL	5	20.00	Using where
 2	DEPENDENT SUBQUERY	partsupp	ref	PRIMARY,i_ps_partkey,i_ps_suppkey	i_ps_partkey	4	dbt3_s001.part.p_partkey	3	100.00	
 2	DEPENDENT SUBQUERY	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.partsupp.ps_suppkey	1	100.00	Using where
 2	DEPENDENT SUBQUERY	nation	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'dbt3_s001.part.p_partkey' of SELECT #2 was resolved in SELECT #1
-Note	1003	/* select#1 */ select `dbt3_s001`.`supplier`.`s_acctbal` AS `s_acctbal`,`dbt3_s001`.`supplier`.`s_name` AS `s_name`,`dbt3_s001`.`nation`.`n_name` AS `n_name`,`dbt3_s001`.`part`.`p_partkey` AS `p_partkey`,`dbt3_s001`.`part`.`p_mfgr` AS `p_mfgr`,`dbt3_s001`.`supplier`.`s_address` AS `s_address`,`dbt3_s001`.`supplier`.`s_phone` AS `s_phone`,`dbt3_s001`.`supplier`.`s_comment` AS `s_comment` from `dbt3_s001`.`part` join `dbt3_s001`.`supplier` join `dbt3_s001`.`partsupp` join `dbt3_s001`.`nation` join `dbt3_s001`.`region` where `dbt3_s001`.`partsupp`.`ps_partkey` = `dbt3_s001`.`part`.`p_partkey` and `dbt3_s001`.`supplier`.`s_suppkey` = `dbt3_s001`.`partsupp`.`ps_suppkey` and `dbt3_s001`.`part`.`p_size` = 9 and `dbt3_s001`.`nation`.`n_nationkey` = `dbt3_s001`.`supplier`.`s_nationkey` and `dbt3_s001`.`region`.`r_regionkey` = `dbt3_s001`.`nation`.`n_regionkey` and `dbt3_s001`.`region`.`r_name` = 'ASIA' and `dbt3_s001`.`part`.`p_type` like '%TIN' and `dbt3_s001`.`partsupp`.`ps_supplycost` = <expr_cache><`dbt3_s001`.`part`.`p_partkey`>((/* select#2 */ select min(`dbt3_s001`.`partsupp`.`ps_supplycost`) from `dbt3_s001`.`partsupp` join `dbt3_s001`.`supplier` join `dbt3_s001`.`nation` join `dbt3_s001`.`region` where `dbt3_s001`.`supplier`.`s_suppkey` = `dbt3_s001`.`partsupp`.`ps_suppkey` and `dbt3_s001`.`nation`.`n_nationkey` = `dbt3_s001`.`supplier`.`s_nationkey` and `dbt3_s001`.`nation`.`n_regionkey` = `dbt3_s001`.`region`.`r_regionkey` and `dbt3_s001`.`region`.`r_name` = 'ASIA' and `dbt3_s001`.`part`.`p_partkey` = `dbt3_s001`.`partsupp`.`ps_partkey`)) order by `dbt3_s001`.`supplier`.`s_acctbal` desc,`dbt3_s001`.`nation`.`n_name`,`dbt3_s001`.`supplier`.`s_name`,`dbt3_s001`.`part`.`p_partkey`
+Note	1003	/* select#1 */ select `dbt3_s001`.`supplier`.`s_acctbal` AS `s_acctbal`,`dbt3_s001`.`supplier`.`s_name` AS `s_name`,`dbt3_s001`.`nation`.`n_name` AS `n_name`,`dbt3_s001`.`part`.`p_partkey` AS `p_partkey`,`dbt3_s001`.`part`.`p_mfgr` AS `p_mfgr`,`dbt3_s001`.`supplier`.`s_address` AS `s_address`,`dbt3_s001`.`supplier`.`s_phone` AS `s_phone`,`dbt3_s001`.`supplier`.`s_comment` AS `s_comment` from `dbt3_s001`.`part` join `dbt3_s001`.`supplier` join `dbt3_s001`.`partsupp` join `dbt3_s001`.`nation` join `dbt3_s001`.`region` where `dbt3_s001`.`partsupp`.`ps_partkey` = `dbt3_s001`.`part`.`p_partkey` and `dbt3_s001`.`supplier`.`s_suppkey` = `dbt3_s001`.`partsupp`.`ps_suppkey` and `dbt3_s001`.`part`.`p_size` = 9 and `dbt3_s001`.`nation`.`n_nationkey` = `dbt3_s001`.`supplier`.`s_nationkey` and `dbt3_s001`.`nation`.`n_regionkey` = `dbt3_s001`.`region`.`r_regionkey` and `dbt3_s001`.`region`.`r_name` = 'ASIA' and `dbt3_s001`.`part`.`p_type` like '%TIN' and `dbt3_s001`.`partsupp`.`ps_supplycost` = <expr_cache><`dbt3_s001`.`part`.`p_partkey`>((/* select#2 */ select min(`dbt3_s001`.`partsupp`.`ps_supplycost`) from `dbt3_s001`.`partsupp` join `dbt3_s001`.`supplier` join `dbt3_s001`.`nation` join `dbt3_s001`.`region` where `dbt3_s001`.`supplier`.`s_suppkey` = `dbt3_s001`.`partsupp`.`ps_suppkey` and `dbt3_s001`.`nation`.`n_nationkey` = `dbt3_s001`.`supplier`.`s_nationkey` and `dbt3_s001`.`nation`.`n_regionkey` = `dbt3_s001`.`region`.`r_regionkey` and `dbt3_s001`.`region`.`r_name` = 'ASIA' and `dbt3_s001`.`part`.`p_partkey` = `dbt3_s001`.`partsupp`.`ps_partkey`)) order by `dbt3_s001`.`supplier`.`s_acctbal` desc,`dbt3_s001`.`nation`.`n_name`,`dbt3_s001`.`supplier`.`s_name`,`dbt3_s001`.`part`.`p_partkey`
 set optimizer_use_condition_selectivity=4;
 explain extended
 select

mysql-test/main/selectivity_innodb.result

@@ -77,8 +77,8 @@ and r_name = 'ASIA'
 order by
 s_acctbal desc, n_name, s_name, p_partkey;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	0.31	Using where; Using temporary; Using filesort
-1	PRIMARY	region	ALL	PRIMARY	NULL	NULL	NULL	5	20.00	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	region	ALL	PRIMARY	NULL	NULL	NULL	5	20.00	Using where; Using temporary; Using filesort
+1	PRIMARY	part	ALL	PRIMARY	NULL	NULL	NULL	200	0.50	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	partsupp	ref	PRIMARY,i_ps_partkey,i_ps_suppkey	PRIMARY	4	dbt3_s001.part.p_partkey	3	100.00	Using where
 1	PRIMARY	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.partsupp.ps_suppkey	1	100.00	Using where
 1	PRIMARY	nation	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	100.00	Using where

mysql-test/main/stat_tables.result

@@ -900,7 +900,7 @@ test	t1	b	2	10	0.0000	4.0000	1.1111	0	NULL	NULL
 analyze
 select * from t1 where a=1 and b=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10.00	2.78	10.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10.00	10.00	10.00	Using where
 drop table t1;
 set @@global.histogram_size=@save_histogram_size;
 # End of 10.4 tests

mysql-test/main/stat_tables_innodb.result

@@ -932,7 +932,7 @@ test	t1	b	2	10	0.0000	4.0000	1.1111	0	NULL	NULL
 analyze
 select * from t1 where a=1 and b=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10.00	2.78	10.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10.00	10.00	10.00	Using where
 drop table t1;
 set @@global.histogram_size=@save_histogram_size;
 # End of 10.4 tests

mysql-test/main/statistics_json.result

@@ -4643,7 +4643,7 @@ Warnings:
 Note	1003	select `test`.`t1_json`.`a` AS `a` from `test`.`t1_json` where `test`.`t1_json`.`a` < 'b-1a'
 analyze select * from t1_json where a > 'zzzzzzzzz';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
-1	SIMPLE	t1_json	ALL	NULL	NULL	NULL	NULL	10	10.00	0.00	0.00	Using where
+1	SIMPLE	t1_json	ALL	NULL	NULL	NULL	NULL	10	10.00	10.00	0.00	Using where
 drop table ten;
 UPDATE mysql.column_stats 
 SET histogram='["not-what-you-expect"]' WHERE table_name='t1_json';

sql/sql_select.cc

@@ -7777,7 +7777,17 @@ static double matching_candidates_in_table(JOIN_TAB *s,
 
   if (with_found_constraint)
     dbl_records-= dbl_records/4;
-  return dbl_records;
+
+  /*
+    Ensure we return at least one row if there is any possibility to have
+    a matching row.  Having rows >= 1.0 helps ensure that when we calculate
+    total rows of joins, the number of resulting rows will not be less
+    after the join. In other words, we assume there is at least one matching
+    row when joining a row with the next table.
+    0.0 is returned only if it is guaranteed there are no matching rows
+    (for example if the table is empty).
+  */
+  return dbl_records ? MY_MAX(dbl_records, 1.0) : 0.0;
 }