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MDEV-18701: Wrong result from query that uses INTERSECT after UNION ALL

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Recalculate distinct pointer if we cut chain of SELECTs
This commit is contained in:
Oleksandr Byelkin
2019-03-11 17:10:20 +01:00
parent 58f3ff7175
commit 6d68a3464e
5 changed files with 69 additions and 13 deletions
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33
mysql-test/main/intersect.result
View File

@ -833,3 +833,36 @@ c1
3
drop table t12,t13,t234;
# End of 10.3 tests
#
# MDEV-18701: Wrong result from query that uses INTERSECT after UNION ALL
#
create table t1 (a int);
insert into t1 values (3), (1), (7), (3), (2), (7), (4);
create table t2 (a int);
insert into t2 values (4), (5), (9), (1), (8), (9);
create table t3 (a int);
insert into t3 values (8), (1), (8), (2), (3), (7), (2);
select * from t1 where a > 4
union all
select * from t2 where a < 5
intersect
select * from t3 where a < 5;
a
7
7
1
explain extended
select * from t1 where a > 4
union all
select * from t2 where a < 5
intersect
select * from t3 where a < 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 7 100.00 Using where
4 UNION <derived2> ALL NULL NULL NULL NULL 6 100.00
2 DERIVED t2 ALL NULL NULL NULL NULL 6 100.00 Using where
3 INTERSECT t3 ALL NULL NULL NULL NULL 7 100.00 Using where
NULL INTERSECT RESULT <intersect2,3> ALL NULL NULL NULL NULL NULL NULL
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 4 union all /* select#4 */ select `__4`.`a` AS `a` from (/* select#2 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where `test`.`t2`.`a` < 5 intersect /* select#3 */ select `test`.`t3`.`a` AS `a` from `test`.`t3` where `test`.`t3`.`a` < 5) `__4`
drop table t1,t2,t3;

27
mysql-test/main/intersect.test
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@ -321,3 +321,30 @@ select * from t13 union select * from t234 intersect select * from t12;
drop table t12,t13,t234;
--echo # End of 10.3 tests
--echo #
--echo # MDEV-18701: Wrong result from query that uses INTERSECT after UNION ALL
--echo #
create table t1 (a int);
insert into t1 values (3), (1), (7), (3), (2), (7), (4);
create table t2 (a int);
insert into t2 values (4), (5), (9), (1), (8), (9);
create table t3 (a int);
insert into t3 values (8), (1), (8), (2), (3), (7), (2);
select * from t1 where a > 4
union all
select * from t2 where a < 5
intersect
select * from t3 where a < 5;
explain extended
select * from t1 where a > 4
union all
select * from t2 where a < 5
intersect
select * from t3 where a < 5;
drop table t1,t2,t3;

1
mysql-test/main/table_value_constr.result
View File

@ -366,6 +366,7 @@ values (1,2);
1 2
1 2
3 4
1 2
# combination of different structures that uses VALUES structures : UNION + UNION ALL
values (1,2),(3,4)
union all

17
sql/sql_lex.cc
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@ -5427,6 +5427,7 @@ SELECT_LEX *LEX::wrap_select_chain_into_derived(SELECT_LEX *sel)
DBUG_RETURN(NULL);
Name_resolution_context *context= &dummy_select->context;
dummy_select->automatic_brackets= FALSE;
sel->distinct= TRUE; // First select has not this attribute (safety)
if (!(unit= dummy_select->attach_selects_chain(sel, context)))
DBUG_RETURN(NULL);
@ -8838,19 +8839,10 @@ void st_select_lex_unit::reset_distinct()
}
void st_select_lex_unit::fix_distinct(st_select_lex_unit *new_unit)
void st_select_lex_unit::fix_distinct()
{
if (union_distinct)
{
if (this != union_distinct->master_unit())
{
DBUG_ASSERT(new_unit == union_distinct->master_unit());
new_unit->union_distinct= union_distinct;
if (union_distinct && this != union_distinct->master_unit())
reset_distinct();
}
else
new_unit->reset_distinct();
}
}
@ -9089,6 +9081,7 @@ bool LEX::parsed_unit_in_brackets(SELECT_LEX_UNIT *unit)
/* There is a priority jump starting from first_in_nest */
if (create_priority_nest(first_in_nest) == NULL)
return true;
unit->fix_distinct();
}
push_select(unit->fake_select_lex);
return false;
@ -9236,6 +9229,7 @@ SELECT_LEX_UNIT *LEX::parsed_select_expr_cont(SELECT_LEX_UNIT *unit,
/* There is a priority jump starting from first_in_nest */
if ((last= create_priority_nest(first_in_nest)) == NULL)
return NULL;
unit->fix_distinct();
}
sel1->first_nested= last->first_nested;
}
@ -9273,6 +9267,7 @@ bool LEX::parsed_body_unit(SELECT_LEX_UNIT *unit)
/* There is a priority jump starting from first_in_nest */
if (create_priority_nest(first_in_nest) == NULL)
return true;
unit->fix_distinct();
}
push_select(unit->fake_select_lex);
return false;

2
sql/sql_lex.h
View File

@ -995,7 +995,7 @@ public:
unit_common_op common_op();
void reset_distinct();
void fix_distinct(st_select_lex_unit *new_unit);
void fix_distinct();
void register_select_chain(SELECT_LEX *first_sel);