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MDEV-4345

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Sampling of selectivity of LIKE predicate.
This commit is contained in:
unknown 2013-04-18 22:22:04 +03:00
parent 8c71e7a383
commit 9441e53653
16 changed files with 464 additions and 7 deletions
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8
mysql-test/r/mysqld--help.result
View File

@ -499,6 +499,9 @@ The following options may be given as the first argument:
optimizer will switch to the original find_best search.
NOTE: The value 63 and its associated behaviour is
deprecated
--optimizer-selectivity-sampling-limit=#
Controls number of record samples to check condition
selectivity
--optimizer-switch=name
optimizer_switch=option=val[,option=val...], where option
is one of {derived_merge, derived_with_keys, firstmatch,
@ -527,7 +530,9 @@ The following options may be given as the first argument:
any index to calculate the cardinality of a partial join,
4 - use histograms to calculate selectivity of range
conditions that are not backed by any index to calculate
the cardinality of a partial join.
the cardinality of a partial join.5 - additionally use
selectivity of certain non-range predicates calculated on
record samples
--performance-schema
Enable the performance schema.
--performance-schema-events-waits-history-long-size=#
@ -1053,6 +1058,7 @@ old-passwords FALSE
old-style-user-limits FALSE
optimizer-prune-level 1
optimizer-search-depth 62
optimizer-selectivity-sampling-limit 5000
optimizer-switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on
optimizer-use-condition-selectivity 1
performance-schema FALSE

83
mysql-test/r/selectivity.result
View File

@ -37,6 +37,89 @@ set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivit
DROP DATABASE IF EXISTS dbt3_s001;
CREATE DATABASE dbt3_s001;
use dbt3_s001;
=== Q2 ===
set optimizer_use_condition_selectivity=5;
explain extended
select
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
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 partsupp ref PRIMARY,i_ps_partkey,i_ps_suppkey PRIMARY 4 dbt3_s001.part.p_partkey 3 100.00 Using where
1 PRIMARY supplier ALL PRIMARY,i_s_nationkey NULL NULL NULL 10 80.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY nation eq_ref PRIMARY,i_n_regionkey PRIMARY 4 dbt3_s001.supplier.s_nationkey 1 100.00 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 PRIMARY 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 `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 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
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
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 region ALL PRIMARY NULL NULL NULL 5 20.00 Using where; Using temporary; Using filesort
1 PRIMARY part ALL PRIMARY NULL NULL NULL 200 2.08 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 ALL PRIMARY,i_s_nationkey NULL NULL NULL 10 80.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY nation eq_ref PRIMARY,i_n_regionkey PRIMARY 4 dbt3_s001.supplier.s_nationkey 1 100.00 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 PRIMARY 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 `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 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`
=== Q15 ===
create view revenue0 (supplier_no, total_revenue) as
select l_suppkey, sum(l_extendedprice * (1 - l_discount))

83
mysql-test/r/selectivity_innodb.result
View File

@ -40,6 +40,89 @@ set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivit
DROP DATABASE IF EXISTS dbt3_s001;
CREATE DATABASE dbt3_s001;
use dbt3_s001;
=== Q2 ===
set optimizer_use_condition_selectivity=5;
explain extended
select
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
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 partsupp ref PRIMARY,i_ps_partkey,i_ps_suppkey PRIMARY 4 dbt3_s001.part.p_partkey 3 100.00 Using where
1 PRIMARY supplier ALL PRIMARY,i_s_nationkey NULL NULL NULL 10 80.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY nation eq_ref PRIMARY,i_n_regionkey PRIMARY 4 dbt3_s001.supplier.s_nationkey 1 100.00 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 PRIMARY 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 `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 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
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
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 region ALL PRIMARY NULL NULL NULL 5 20.00 Using where; Using temporary; Using filesort
1 PRIMARY part ALL PRIMARY NULL NULL NULL 200 2.08 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 ALL PRIMARY,i_s_nationkey NULL NULL NULL 10 80.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY nation eq_ref PRIMARY,i_n_regionkey PRIMARY 4 dbt3_s001.supplier.s_nationkey 1 100.00 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 PRIMARY 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 `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 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`
=== Q15 ===
create view revenue0 (supplier_no, total_revenue) as
select l_suppkey, sum(l_extendedprice * (1 - l_discount))

1
mysql-test/suite/sys_vars/r/all_vars.result
View File

@ -10,5 +10,6 @@ there should be *no* long test name listed below:
select distinct variable_name as `there should be *no* variables listed below:` from t2
left join t1 on variable_name=test_name where test_name is null;
there should be *no* variables listed below:
optimizer_selectivity_sampling_limit
drop table t1;
drop table t2;

59
mysql-test/t/selectivity.test
View File

@ -56,6 +56,64 @@ customer, lineitem, nation, orders, part, partsupp, region, supplier;
--enable_result_log
--enable_query_log
--echo === Q2 ===
set optimizer_use_condition_selectivity=5;
explain extended
select
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
)
order by
s_acctbal desc, n_name, s_name, p_partkey;
set optimizer_use_condition_selectivity=4;
explain extended
select
s_acctbal, s_name, n_name, p_partkey, p_mfgr, s_address, s_phone, s_comment
from
part, supplier, partsupp, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and p_size = 9
and p_type like '%TIN'
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
and ps_supplycost = (
select
min(ps_supplycost)
from
partsupp, supplier, nation, region
where
p_partkey = ps_partkey
and s_suppkey = ps_suppkey
and s_nationkey = n_nationkey
and n_regionkey = r_regionkey
and r_name = 'ASIA'
)
order by
s_acctbal desc, n_name, s_name, p_partkey;
--echo === Q15 ===
@ -230,7 +288,6 @@ flush table nation;
eval EXPLAIN EXTENDED $Q20;
eval $Q20;
DROP DATABASE dbt3_s001;
set histogram_type=@save_histogram_type;

15
sql/item.h
View File

@ -548,6 +548,14 @@ typedef bool (Item::*Item_analyzer) (uchar **argp);
typedef Item* (Item::*Item_transformer) (uchar *arg);
typedef void (*Cond_traverser) (const Item *item, void *arg);
struct st_cond_statistic;
struct find_selective_predicates_list_processor_data
{
TABLE *table;
List<st_cond_statistic> list;
};
class Item_equal;
class COND_EQUAL;
@ -1108,6 +1116,11 @@ public:
return (this->*processor)(arg);
}
virtual bool walk_top_and(Item_processor processor, uchar *arg)
{
return (this->*processor)(arg);
}
virtual Item* transform(Item_transformer transformer, uchar *arg);
/*
@ -1174,6 +1187,8 @@ public:
return FALSE;
}
virtual bool exists2in_processor(uchar *opt_arg) { return 0; }
virtual bool find_selective_predicates_list_processor(uchar *opt_arg)
{ return 0; }
/* To call bool function for all arguments */
struct bool_func_call_args

33
sql/item_cmpfunc.cc
View File

@ -4428,6 +4428,16 @@ bool Item_cond::walk(Item_processor processor, bool walk_subquery, uchar *arg)
return Item_func::walk(processor, walk_subquery, arg);
}
bool Item_cond_and::walk_top_and(Item_processor processor, uchar *arg)
{
List_iterator_fast<Item> li(list);
Item *item;
while ((item= li++))
if (item->walk_top_and(processor, arg))
return 1;
return Item_cond::walk_top_and(processor, arg);
}
/**
Transform an Item_cond object with a transformer callback function.
@ -4940,6 +4950,7 @@ bool Item_func_like::fix_fields(THD *thd, Item **ref)
turboBM_compute_bad_character_shifts();
DBUG_PRINT("info",("done"));
}
use_sampling= ((*first == wild_many || *first == wild_one) && len > 2);
}
}
return FALSE;
@ -4951,6 +4962,28 @@ void Item_func_like::cleanup()
Item_bool_func2::cleanup();
}
bool Item_func_like::find_selective_predicates_list_processor(uchar *arg)
{
find_selective_predicates_list_processor_data *data=
(find_selective_predicates_list_processor_data *) arg;
if (use_sampling && used_tables() == data->table->map)
{
COND_STATISTIC *stat= (COND_STATISTIC *)sql_alloc(sizeof(COND_STATISTIC));
if (!stat)
return TRUE;
stat->cond= this;
Item *arg0= args[0]->real_item();
if (args[1]->const_item() && arg0->type() == FIELD_ITEM)
stat->field_arg= ((Item_field *)arg0)->field;
else
stat->field_arg= NULL;
data->list.push_back(stat);
}
return FALSE;
}
/**
@brief Compile regular expression.

8
sql/item_cmpfunc.h
View File

@ -1487,8 +1487,9 @@ class Item_func_like :public Item_bool_func2
enum { alphabet_size = 256 };
Item *escape_item;
bool escape_used_in_parsing;
bool use_sampling;
public:
int escape;
@ -1496,7 +1497,7 @@ public:
Item_func_like(Item *a,Item *b, Item *escape_arg, bool escape_used)
:Item_bool_func2(a,b), canDoTurboBM(FALSE), pattern(0), pattern_len(0),
bmGs(0), bmBc(0), escape_item(escape_arg),
escape_used_in_parsing(escape_used) {}
escape_used_in_parsing(escape_used), use_sampling(0) {}
longlong val_int();
enum Functype functype() const { return LIKE_FUNC; }
optimize_type select_optimize() const;
@ -1504,6 +1505,8 @@ public:
const char *func_name() const { return "like"; }
bool fix_fields(THD *thd, Item **ref);
void cleanup();
bool find_selective_predicates_list_processor(uchar *arg);
};
@ -1914,6 +1917,7 @@ public:
Item *neg_transformer(THD *thd);
void mark_as_condition_AND_part(TABLE_LIST *embedding);
virtual uint exists2in_reserved_items() { return list.elements; };
bool walk_top_and(Item_processor processor, uchar *arg);
};
inline bool is_cond_and(Item *item)

69
sql/opt_range.cc
View File

@ -3530,7 +3530,74 @@ bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item *cond)
}
}
}
}
}
/* Calculate selectivity of probably highly selective predicates */
ulong check_rows=
min(thd->variables.optimizer_selectivity_sampling_limit,
(ulong) (table_records * SELECTIVITY_SAMPLING_SHARE));
if (cond && check_rows > SELECTIVITY_SAMPLING_THRESHOLD &&
thd->variables.optimizer_use_condition_selectivity > 4)
{
find_selective_predicates_list_processor_data *dt=
(find_selective_predicates_list_processor_data *)
alloc_root(thd->mem_root,
sizeof(find_selective_predicates_list_processor_data));
if (!dt)
DBUG_RETURN(TRUE);
dt->list.empty();
dt->table= table;
if (cond->walk(&Item::find_selective_predicates_list_processor, 0,
(uchar*) dt))
DBUG_RETURN(TRUE);
if (dt->list.elements > 0)
{
check_rows= check_selectivity(thd, check_rows, table, &dt->list);
if (check_rows > SELECTIVITY_SAMPLING_THRESHOLD)
{
COND_STATISTIC *stat;
List_iterator_fast<COND_STATISTIC> it(dt->list);
double examined_rows= check_rows;
while ((stat= it++))
{
if (!stat->positive)
{
DBUG_PRINT("info", ("To avoid 0 assigned 1 to the counter"));
stat->positive= 1; // avoid 0
}
DBUG_PRINT("info", ("The predicate selectivity : %g",
(double)stat->positive / examined_rows));
double selectivity= ((double)stat->positive) / examined_rows;
table->cond_selectivity*= selectivity;
/*
If a field is involved then we register its selectivity in case
there in an equality with the field.
For example in case
t1.a LIKE "%bla%" and t1.a = t2.b
the selectivity we have found could be used also for t2.
*/
if (stat->field_arg)
{
stat->field_arg->cond_selectivity*= selectivity;
if (stat->field_arg->next_equal_field)
{
for (Field *next_field= stat->field_arg->next_equal_field;
next_field != stat->field_arg;
next_field= next_field->next_equal_field)
{
next_field->cond_selectivity*= selectivity;
next_field->table->cond_selectivity*= selectivity;
}
}
}
}
}
/* This list and its elements put to mem_root so should not be freed */
table->cond_selectivity_sampling_explain= &dt->list;
}
}
DBUG_RETURN(FALSE);
}

7
sql/opt_range.h
View File

@ -1051,4 +1051,11 @@ void store_key_image_to_rec(Field *field, uchar *ptr, uint len);
extern String null_string;
/* check this number of rows (default value) */
#define SELECTIVITY_SAMPLING_LIMIT 5000
/* but no more then this part of table (10%) */
#define SELECTIVITY_SAMPLING_SHARE 0.10
/* do not check if we are going check less then this number of records */
#define SELECTIVITY_SAMPLING_THRESHOLD 10
#endif

1
sql/sql_class.h
View File

@ -505,6 +505,7 @@ typedef struct system_variables
ulong net_write_timeout;
ulong optimizer_prune_level;
ulong optimizer_search_depth;
ulong optimizer_selectivity_sampling_limit;
ulong optimizer_use_condition_selectivity;
ulong use_stat_tables;
ulong histogram_size;

72
sql/sql_select.cc
View File

@ -23972,6 +23972,78 @@ uint get_index_for_order(ORDER *order, TABLE *table, SQL_SELECT *select,
return MAX_KEY;
}
/*
Count how much times conditions are true for several first rows of the table
@param thd thread handle
@param rows_to_read how much rows to check
@param table table which should be checked
@conds conds list of conditions and countars for them
@return number of really checked rows or 0 in case of error or empty table
*/
ulong check_selectivity(THD *thd,
ulong rows_to_read,
TABLE *table,
List<COND_STATISTIC> *conds)
{
ulong count= 0;
COND_STATISTIC *cond;
List_iterator_fast<COND_STATISTIC> it(*conds);
handler *file= table->file;
uchar *record= table->record[0];
int error= 0;
DBUG_ENTER("check_selectivity");
DBUG_ASSERT(rows_to_read > 0);
while ((cond= it++))
{
DBUG_ASSERT(cond->cond);
DBUG_ASSERT(cond->cond->used_tables() == table->map);
cond->positive= 0;
}
it.rewind();
if (file->ha_rnd_init_with_error(1))
DBUG_RETURN(0);
do
{
error= file->ha_rnd_next(record);
if (thd->killed)
{
thd->send_kill_message();
count= 0;
goto err;
}
if (error)
{
if (error == HA_ERR_RECORD_DELETED)
continue;
if (error == HA_ERR_END_OF_FILE)
break;
goto err;
}
count++;
while ((cond= it++))
{
if (cond->cond->val_bool())
cond->positive++;
}
it.rewind();
} while (count < rows_to_read);
file->ha_rnd_end();
DBUG_RETURN(count);
err:
DBUG_PRINT("error", ("error %d", error));
file->ha_rnd_end();
DBUG_RETURN(0);
}
/**
@} (end of group Query_Optimizer)

13
sql/sql_select.h
View File

@ -1855,4 +1855,17 @@ void setup_tmp_table_column_bitmaps(TABLE *table, uchar *bitmaps);
double prev_record_reads(POSITION *positions, uint idx, table_map found_ref);
void fix_list_after_tbl_changes(SELECT_LEX *new_parent, List<TABLE_LIST> *tlist);
struct st_cond_statistic
{
Item *cond;
Field *field_arg;
ulong positive;
};
typedef struct st_cond_statistic COND_STATISTIC;
ulong check_selectivity(THD *thd,
ulong rows_to_read,
TABLE *table,
List<COND_STATISTIC> *conds);
#endif /* SQL_SELECT_INCLUDED */

15
sql/sys_vars.cc
View File

@ -56,6 +56,7 @@
#endif /* WITH_PERFSCHEMA_STORAGE_ENGINE */
#include "threadpool.h"
#include "sql_repl.h"
#include "opt_range.h"
/*
The rule for this file: everything should be 'static'. When a sys_var
@ -1533,6 +1534,14 @@ static Sys_var_ulong Sys_optimizer_prune_level(
SESSION_VAR(optimizer_prune_level), CMD_LINE(REQUIRED_ARG),
VALID_RANGE(0, 1), DEFAULT(1), BLOCK_SIZE(1));
static Sys_var_ulong Sys_optimizer_selectivity_sampling_limit(
"optimizer_selectivity_sampling_limit",
"Controls number of record samples to check condition selectivity",
SESSION_VAR(optimizer_selectivity_sampling_limit),
CMD_LINE(REQUIRED_ARG),
VALID_RANGE(SELECTIVITY_SAMPLING_THRESHOLD, UINT_MAX),
DEFAULT(SELECTIVITY_SAMPLING_LIMIT), BLOCK_SIZE(1));
static Sys_var_ulong Sys_optimizer_use_condition_selectivity(
"optimizer_use_condition_selectivity",
"Controls selectivity of which conditions the optimizer takes into "
@ -1548,9 +1557,11 @@ static Sys_var_ulong Sys_optimizer_use_condition_selectivity(
"not backed by any index to calculate the cardinality of a partial join, "
"4 - use histograms to calculate selectivity of range conditions that "
"are not backed by any index to calculate the cardinality of "
"a partial join.",
"a partial join."
"5 - additionally use selectivity of certain non-range predicates "
"calculated on record samples",
SESSION_VAR(optimizer_use_condition_selectivity), CMD_LINE(REQUIRED_ARG),
VALID_RANGE(1, 4), DEFAULT(1), BLOCK_SIZE(1));
VALID_RANGE(1, 5), DEFAULT(1), BLOCK_SIZE(1));
/** Warns about deprecated value 63 */
static bool fix_optimizer_search_depth(sys_var *self, THD *thd,

1
sql/table.cc
View File

@ -3891,6 +3891,7 @@ void TABLE::init(THD *thd, TABLE_LIST *tl)
reginfo.impossible_range= 0;
created= TRUE;
cond_selectivity= 1.0;
cond_selectivity_sampling_explain= NULL;
/* Catch wrong handling of the auto_increment_field_not_null. */
DBUG_ASSERT(!auto_increment_field_not_null);

3
sql/table.h
View File

@ -1038,6 +1038,8 @@ enum index_hint_type
INDEX_HINT_FORCE
};
struct st_cond_statistic;
#define CHECK_ROW_FOR_NULLS_TO_REJECT (1 << 0)
#define REJECT_ROW_DUE_TO_NULL_FIELDS (1 << 1)
@ -1163,6 +1165,7 @@ public:
ha_rows quick_condition_rows;
double cond_selectivity;
List<st_cond_statistic> *cond_selectivity_sampling_explain;
table_map map; /* ID bit of table (1,2,4,8,16...) */