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Return >= 1 from matching_candidates_in_table if records > 0.0

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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.
This commit is contained in:
Monty
2021-10-08 01:40:59 +03:00
committed by Sergei Petrunia
parent b67144893a
commit bc9805e954
14 changed files with 50 additions and 39 deletions
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8
mysql-test/main/join_nested_jcl6.result
View File

@ -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)

2
mysql-test/main/opt_trace.result
View File

@ -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;

10
mysql-test/main/opt_trace_selectivity.result
View File

@ -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
}
]

2
mysql-test/main/range.result
View File

@ -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"
}

2
mysql-test/main/range_mrr_icp.result
View File

@ -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"

16
mysql-test/main/rowid_filter.result
View File

@ -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"

20
mysql-test/main/rowid_filter_innodb.result
View File

@ -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;

1
mysql-test/main/rowid_filter_innodb.test
View File

@ -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;

6
mysql-test/main/selectivity.result
View File

@ -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

4
mysql-test/main/selectivity_innodb.result
View File

@ -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

2
mysql-test/main/stat_tables.result
View File

@ -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

2
mysql-test/main/stat_tables_innodb.result
View File

@ -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

2
mysql-test/main/statistics_json.result
View File

@ -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';

12
sql/sql_select.cc
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@ -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;
}