mirror of
https://github.com/MariaDB/server.git
synced 2025-01-17 20:42:30 +01:00
26a3d567c9
MDEV-5984: EITS: Incorrect filtered% value for single-table select with range access
- Fix calculate_cond_selectivity_for_table() to work correctly with range accesses
over multi-component keys:
= First, take selectivity of all possible range scans into account. Remember which
fields were used bt the range scans.
= Then, calculate selectivity produced by sargable predicates on fields. If a
field was used in a possible range access, assume its selectivity is already
taken into account.
- Fix table_cond_selectivity(): when quick select is used, selectivity of
COND(table) is taken into account in matching_candidates_in_table(). In
table_cond_selectivity() we should not apply it for the second time.
147 lines
6.6 KiB
Text
147 lines
6.6 KiB
Text
#
|
|
# Engine-agnostic tests for statistics-based selectivity calculations.
|
|
# - selectivity tests that depend on the engine should go into
|
|
# t/selectivity.test. That test is run with myisam/innodb/xtradb.
|
|
# - this file is for tests that don't depend on the engine.
|
|
#
|
|
drop table if exists t0,t1,t2,t3;
|
|
select @@global.use_stat_tables;
|
|
@@global.use_stat_tables
|
|
COMPLEMENTARY
|
|
select @@session.use_stat_tables;
|
|
@@session.use_stat_tables
|
|
COMPLEMENTARY
|
|
set @save_use_stat_tables=@@use_stat_tables;
|
|
set use_stat_tables='preferably';
|
|
set @save_optimizer_use_condition_selectivity=@@optimizer_use_condition_selectivity;
|
|
set @save_histogram_size=@@histogram_size;
|
|
set @save_histogram_type=@@histogram_type;
|
|
#
|
|
# MDEV-5917: EITS: different order of predicates in IN (...) causes different estimates
|
|
#
|
|
create table t1(a int);
|
|
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
|
|
create table t2 (col1 int);
|
|
# one value in 1..100 range
|
|
insert into t2 select A.a + B.a*10 from t1 A, t1 B;
|
|
# ten values in 100...200 range
|
|
insert into t2 select 100 + A.a + B.a*10 from t1 A, t1 B, t1 C;
|
|
set histogram_type='SINGLE_PREC_HB';
|
|
set histogram_size=100;
|
|
set optimizer_use_condition_selectivity=4;
|
|
analyze table t2 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t2 analyze status Engine-independent statistics collected
|
|
test.t2 analyze status OK
|
|
# The following two must have the same in 'Extra' column:
|
|
explain extended select * from t2 where col1 IN (20, 180);
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 1100 1.35 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t2`.`col1` AS `col1` from `test`.`t2` where (`test`.`t2`.`col1` in (20,180))
|
|
explain extended select * from t2 where col1 IN (180, 20);
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 1100 1.35 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t2`.`col1` AS `col1` from `test`.`t2` where (`test`.`t2`.`col1` in (180,20))
|
|
drop table t1, t2;
|
|
#
|
|
# MDEV-5926: EITS: Histogram estimates for column=least_possible_value are wrong
|
|
#
|
|
create table t0(a int);
|
|
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
|
|
create table t1(a int);
|
|
insert into t1 select A.a from t0 A, t0 B, t0 C;
|
|
set histogram_size=20;
|
|
set histogram_type='single_prec_hb';
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
set use_stat_tables='preferably';
|
|
set optimizer_use_condition_selectivity=4;
|
|
# Should select about 10%:
|
|
explain extended select * from t1 where a=2;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 9.52 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = 2)
|
|
# Should select about 10%:
|
|
explain extended select * from t1 where a=1;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 9.52 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = 1)
|
|
# Must not have filtered=100%:
|
|
explain extended select * from t1 where a=0;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 9.52 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = 0)
|
|
# Again, must not have filtered=100%:
|
|
explain extended select * from t1 where a=-1;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 9.52 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = <cache>(-(1)))
|
|
drop table t0, t1;
|
|
#
|
|
# MDEV-4362: Selectivity estimates for IN (...) do not depend on whether the values are in range
|
|
#
|
|
create table t1 (col1 int);
|
|
set @a=-1;
|
|
create table t2 (a int) select (@a:=@a+1) as a from information_schema.session_variables A limit 100;
|
|
insert into t1 select A.a from t2 A, t2 B where A.a < 100 and B.a < 100;
|
|
select min(col1), max(col1), count(*) from t1;
|
|
min(col1) max(col1) count(*)
|
|
0 99 10000
|
|
set histogram_size=100;
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
explain extended select * from t1 where col1 in (1,2,3);
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 10000 3.37 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`col1` AS `col1` from `test`.`t1` where (`test`.`t1`.`col1` in (1,2,3))
|
|
# Must not cause fp division by zero, or produce nonsense numbers:
|
|
explain extended select * from t1 where col1 in (-1,-2,-3);
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 10000 5.94 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`col1` AS `col1` from `test`.`t1` where (`test`.`t1`.`col1` in (<cache>(-(1)),<cache>(-(2)),<cache>(-(3))))
|
|
explain extended select * from t1 where col1<=-1;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 10000 1.00 Using where
|
|
Warnings:
|
|
Note 1003 select `test`.`t1`.`col1` AS `col1` from `test`.`t1` where (`test`.`t1`.`col1` <= <cache>(-(1)))
|
|
drop table t1, t2;
|
|
#
|
|
# MDEV-5984: EITS: Incorrect filtered% value for single-table select with range access
|
|
#
|
|
create table t1(a int);
|
|
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
|
|
create table t2 (a int, b int, col1 varchar(64), col2 varchar(64), key(a,b));
|
|
insert into t2 select A.a+10*B.a, C.a+10*D.a, 'filler-data1', 'filler-data2' from t1 A, t1 B, t1 C, t1 D;
|
|
set histogram_size=100;
|
|
set optimizer_use_condition_selectivity=4;
|
|
set use_stat_tables='preferably';
|
|
analyze table t2 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t2 analyze status Engine-independent statistics collected
|
|
test.t2 analyze status Table is already up to date
|
|
# This must show filtered=100%:
|
|
explain extended select * from t2 where a in (1,2,3) and b in (1,2,3);
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t2 range a a 10 NULL 9 100.00 Using index condition
|
|
Warnings:
|
|
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`col1` AS `col1`,`test`.`t2`.`col2` AS `col2` from `test`.`t2` where ((`test`.`t2`.`a` in (1,2,3)) and (`test`.`t2`.`b` in (1,2,3)))
|
|
drop table t2, t1;
|
|
#
|
|
# End of the test file
|
|
#
|
|
set use_stat_tables= @save_use_stat_tables;
|
|
set histogram_type=@save_histogram_type;
|
|
set histogram_size=@save_histogram_size;
|
|
set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
|