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Commit c00c12df authored by Monty's avatar Monty
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MDEV-30659 Server crash on EXPLAIN SELECT/SELECT on table with engine Aria for LooseScan Strategy 

The issue was that Loose_scan_opt::save_to_position() did not take
into account records_out from best_access_path()
parent 0dffeeab
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Showing with 193 additions and 20 deletions
mysql-test/main/selectivity.result
View file @ c00c12df
......@@ -2011,3 +2011,57 @@ INSERT INTO t2 VALUES (1),(2);
SELECT STRAIGHT_JOIN pk FROM t1 JOIN t2 ON a = pk WHERE b >= 'A' ORDER BY t2.pk LIMIT 8 OFFSET 1;
pk
DROP TABLE t1, t2;
#
# MDEV-30659 Server crash on EXPLAIN SELECT/SELECT on table with
# engine Aria for LooseScan Strategy
#
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1(c1,c2,c3)
values (1,1,1), (1,2,2), (1,3,3),
(2,1,4), (2,2,5), (2,3,6),
(2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and
c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 1
drop table t1;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
create trigger trg_t1 before update on t1 for each row
begin
set new.old_c1=old.c1;
set new.old_c2=old.c2;
end;
/
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
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
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 1
drop trigger trg_t1;
drop table t1,t2;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 2
drop table t1,t2;
mysql-test/main/selectivity.test
View file @ c00c12df
......@@ -1376,3 +1376,54 @@ INSERT INTO t2 VALUES (1),(2);
SELECT STRAIGHT_JOIN pk FROM t1 JOIN t2 ON a = pk WHERE b >= 'A' ORDER BY t2.pk LIMIT 8 OFFSET 1;
DROP TABLE t1, t2;
--echo #
--echo # MDEV-30659 Server crash on EXPLAIN SELECT/SELECT on table with
--echo # engine Aria for LooseScan Strategy
--echo #
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1(c1,c2,c3)
values (1,1,1), (1,2,2), (1,3,3),
(2,1,4), (2,2,5), (2,3,6),
(2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and
c2 >= 3 order by c2;
drop table t1;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
delimiter /;
create trigger trg_t1 before update on t1 for each row
begin
set new.old_c1=old.c1;
set new.old_c2=old.c2;
end;
/
delimiter ;/
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
analyze table t1 persistent for all;
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
drop trigger trg_t1;
drop table t1,t2;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
drop table t1,t2;
mysql-test/main/selectivity_innodb.result
View file @ c00c12df
......@@ -2018,6 +2018,60 @@ INSERT INTO t2 VALUES (1),(2);
SELECT STRAIGHT_JOIN pk FROM t1 JOIN t2 ON a = pk WHERE b >= 'A' ORDER BY t2.pk LIMIT 8 OFFSET 1;
pk
DROP TABLE t1, t2;
#
# MDEV-30659 Server crash on EXPLAIN SELECT/SELECT on table with
# engine Aria for LooseScan Strategy
#
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1(c1,c2,c3)
values (1,1,1), (1,2,2), (1,3,3),
(2,1,4), (2,2,5), (2,3,6),
(2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and
c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 1
drop table t1;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
create trigger trg_t1 before update on t1 for each row
begin
set new.old_c1=old.c1;
set new.old_c2=old.c2;
end;
/
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
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
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 1
drop trigger trg_t1;
drop table t1,t2;
create table t1 (old_c1 integer, old_c2 integer, c1 integer,
c2 integer, c3 integer) engine=aria;
insert into t1 (c1,c2,c3) values
(1,1,1), (1,2,2), (1,3,3), (2,1,4), (2,2,5), (2,3,6), (2,4,7), (2,5,8);
create index t1_c2 on t1 (c2,c1);
create table t2 as select * from t1;
truncate table t1;
insert into t1 select * from t2;
explain select * from t1 where t1.c2 in (select a.c2 from t1 a) and c2 >= 3 order by c2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a range t1_c2 t1_c2 5 NULL 5 Using where; Using index; LooseScan
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 2
drop table t1,t2;
set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
set @tmp_ust= @@use_stat_tables;
set @tmp_oucs= @@optimizer_use_condition_selectivity;
......
mysql-test/main/subselect_sj2.result
View file @ c00c12df
......@@ -736,8 +736,8 @@ alter table t3 add primary key(id), add key(a);
The following must use loose index scan over t3, key a:
explain select count(a) from t2 where a in ( SELECT a FROM t3);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index a a 5 NULL 1000 Using where; Using index
1 PRIMARY t3 ref a a 5 test.t2.a 30 Using index; FirstMatch(t2)
1 PRIMARY t3 index a a 5 NULL 30000 Using where; Using index; LooseScan
1 PRIMARY t2 ref a a 5 test.t3.a 1 Using index
select count(a) from t2 where a in ( SELECT a FROM t3);
count(a)
1000
......
mysql-test/main/subselect_sj2_jcl6.result
View file @ c00c12df
......@@ -745,8 +745,8 @@ alter table t3 add primary key(id), add key(a);
The following must use loose index scan over t3, key a:
explain select count(a) from t2 where a in ( SELECT a FROM t3);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index a a 5 NULL 1000 Using where; Using index
1 PRIMARY t3 ref a a 5 test.t2.a 30 Using index; FirstMatch(t2)
1 PRIMARY t3 index a a 5 NULL 30000 Using where; Using index; LooseScan
1 PRIMARY t2 ref a a 5 test.t3.a 1 Using index
select count(a) from t2 where a in ( SELECT a FROM t3);
count(a)
1000
......
mysql-test/main/subselect_sj2_mat.result
View file @ c00c12df
......@@ -738,8 +738,8 @@ alter table t3 add primary key(id), add key(a);
The following must use loose index scan over t3, key a:
explain select count(a) from t2 where a in ( SELECT a FROM t3);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index a a 5 NULL 1000 Using where; Using index
1 PRIMARY t3 ref a a 5 test.t2.a 30 Using index; FirstMatch(t2)
1 PRIMARY t3 index a a 5 NULL 30000 Using where; Using index; LooseScan
1 PRIMARY t2 ref a a 5 test.t3.a 1 Using index
select count(a) from t2 where a in ( SELECT a FROM t3);
count(a)
1000
......
mysql-test/main/subselect_sj_mat.result
View file @ c00c12df
......@@ -108,7 +108,7 @@ explain extended
select * from t1i where a1 in (select b1 from t2i where b1 > '0');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i3 it2i1 # NULL 5 50.00 Using where; Using index; LooseScan
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 20.00
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 40.00
Warnings:
Note 1003 select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) where `test`.`t1i`.`a1` = `test`.`t2i`.`b1` and `test`.`t2i`.`b1` > '0'
select * from t1i where a1 in (select b1 from t2i where b1 > '0');
......@@ -131,7 +131,7 @@ explain extended
select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i2,it2i3 it2i3 # NULL 5 50.00 Using where; Using index; LooseScan
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 20.00
1 PRIMARY t1i ref _it1_idx _it1_idx # _ref_ 1 40.00
Warnings:
Note 1003 select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) where `test`.`t1i`.`a1` = `test`.`t2i`.`b1` and `test`.`t1i`.`a2` = `test`.`t2i`.`b2` and `test`.`t2i`.`b1` > '0'
select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
......@@ -277,7 +277,7 @@ explain extended
select * from t1i where (a1, a2) in (select b1, b2 from t2i order by b1, b2);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i2,it2i3 it2i3 18 NULL 5 50.00 Using where; Using index; LooseScan
1 PRIMARY t1i ref it1i1,it1i2,it1i3 it1i3 18 test.t2i.b1,test.t2i.b2 1 20.00 Using index
1 PRIMARY t1i ref it1i1,it1i2,it1i3 it1i3 18 test.t2i.b1,test.t2i.b2 1 40.00 Using index
Warnings:
Note 1003 select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) where `test`.`t1i`.`a1` = `test`.`t2i`.`b1` and `test`.`t1i`.`a2` = `test`.`t2i`.`b2`
select * from t1i where (a1, a2) in (select b1, b2 from t2i order by b1, b2);
......@@ -349,7 +349,7 @@ where (a1, a2) in (select b1, b2 from t2i where b1 > '0') and
where (c1, c2) in (select b1, b2 from t2i where b2 > '0'));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2i index it2i1,it2i2,it2i3 # # # 5 50.00 #
1 PRIMARY t1i ref it1i1,it1i2,it1i3 # # # 1 20.00 #
1 PRIMARY t1i ref it1i1,it1i2,it1i3 # # # 1 40.00 #
1 PRIMARY t3i ref it3i1,it3i2,it3i3 # # # 1 100.00 #
1 PRIMARY t2i ref it2i1,it2i2,it2i3 # # # 1 60.00 #
Warnings:
......@@ -433,7 +433,7 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
4 MATERIALIZED t3 ALL NULL # # # 4 100.00 #
3 MATERIALIZED t3 ALL NULL # # # 4 100.00 #
7 UNION t2i index it2i1,it2i2,it2i3 # # # 5 50.00 #
7 UNION t1i ref it1i1,it1i2,it1i3 # # # 1 20.00 #
7 UNION t1i ref it1i1,it1i2,it1i3 # # # 1 40.00 #
7 UNION t3i ref it3i1,it3i2,it3i3 # # # 1 100.00 #
7 UNION t2i ref it2i1,it2i2,it2i3 # # # 1 60.00 #
NULL UNION RESULT <union1,7> ALL NULL # # # NULL NULL #
......
sql/opt_subselect.h
View file @ c00c12df
......@@ -294,14 +294,30 @@ class Loose_scan_opt
}
}
void save_to_position(JOIN_TAB *tab, double record_count, POSITION *pos)
void save_to_position(JOIN_TAB *tab, double record_count,
double *records_out,
POSITION *pos)
{
pos->read_time= best_loose_scan_cost;
if (best_loose_scan_cost != DBL_MAX)
{
/*
best_loose_scan_records can be smaller than records_out in
the case where we use index statistics on a result column
to estimate the number of unique row combinations.
Example from selectivity.test:
SELECT * from t1 where t1.c2 in (select a.c2 from t1 a)
and c2 >= 3 order by c2;
In this case range optimizer tells us that a has records_out of 5
while index statistics tells us that a.c2 has only 4 unique
values.
*/
set_if_smaller(*records_out, best_loose_scan_records);
pos->loops= record_count;
pos->records_read= best_loose_scan_records;
pos->records_init= pos->records_out= pos->records_read;
pos->records_init= pos->records_read;
pos->records_out= *records_out;
pos->key= best_loose_scan_start_key;
pos->cond_selectivity= 1.0;
pos->loosescan_picker.loosescan_key= best_loose_scan_key;
......
sql/sql_select.cc
View file @ c00c12df
......@@ -8151,7 +8151,6 @@ best_access_path(JOIN *join,
best.use_join_buffer= FALSE;
best.spl_plan= 0;
pos->loops= record_count;
disable_jbuf= disable_jbuf || idx == join->const_tables;
trace_wrapper.add_table_name(s);
......@@ -9303,8 +9302,8 @@ best_access_path(JOIN *join,
crash_if_first_double_is_bigger(best.records_out, best.records_read);
/* Update the cost information for the current partial plan */
pos->loops= record_count;
pos->records_init= best.records_read;
pos->record_combinations= record_count;
pos->records_after_filter= best.records_after_filter;
pos->records_read= best.records;
pos->records_out= best.records_out;
......@@ -9324,7 +9323,8 @@ best_access_path(JOIN *join,
key_dependent & remaining_tables);
pos->refills= best.refills;
loose_scan_opt.save_to_position(s, record_count, loose_scan_pos);
loose_scan_opt.save_to_position(s, record_count, &pos->records_out,
loose_scan_pos);
if (!best.key &&
idx == join->const_tables && // First table
......@@ -11793,7 +11793,7 @@ prev_record_reads(const POSITION *position, uint idx, table_map found_ref,
if (pos->type == JT_EQ_REF)
found= COST_MULT(found, pos->identical_keys);
else if (pos->use_join_buffer)
found= COST_MULT(found, pos->record_combinations / pos->refills);
found= COST_MULT(found, pos->loops / pos->refills);
}
break;
}
sql/sql_select.h
View file @ c00c12df
......@@ -1012,9 +1012,6 @@ class POSITION
*/
double records_out;
/* record combinations before this table */
double record_combinations;
/* Values from prev_record_reads call for EQ_REF table*/
double prev_record_reads, identical_keys;
......@@ -1028,6 +1025,7 @@ class POSITION
*/
double read_time;
/* record combinations before this table */
double loops;
double prefix_record_count;
......
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