Commit 59269b1d authored by Ole John Aske's avatar Ole John Aske

Fix for bug#57030: ('BETWEEN' evaluation is incorrect')

            
Root cause for this bug is that the optimizer try to detect&
optimize the special case:
      
'<field>  BETWEEN c1 AND c1' and handle this as the condition '<field>  = c1'
            
This was implemented inside add_key_field(.. *field, *value[]...)
which assumed field to refer key Field, and value[] to refer a [low...high]
constant pair. value[0] and value[1] was then compared for equality.
            
In a 'normal' BETWEEN condition of the form '<field>  BETWEEN val1 and val2' the
BETWEEN operation is represented with an argementlist containing the
values [<field>, val1, val2] - add_key_field() is then called with
parameters field=<field>, *value=val1.
            
However, if the BETWEEN predicate specified:
            
 1)  '<const1>  BETWEEN<const2>  AND<field>
            
the 'field' and 'value' arguments to add_key_field() had to be swapped.
This was implemented by trying to cheat add_key_field() to handle it like:
            
 2) '<const1>  GE<const2>  AND<const1>  LE<field>'
            
As we didn't really replace the BETWEEN operation with 'ge' and 'le',
add_key_field() still handled it as a 'BETWEEN' and compared the (swapped)
arguments<const1>  and<const2>  for equality. If they was equal, the
condition 1) was incorrectly 'optimized' to:
            
 3) '<field>  EQ <const1>'
            
This fix moves this optimization of '<field>  BETWEEN c1 AND c1' into
add_key_fields() which then calls add_key_equal_fields() to collect 
key equality / comparison for the key fields in the BETWEEN condition.
parent 2d2f80e0
......@@ -1666,4 +1666,105 @@ c_key c_notkey
1 1
3 3
DROP TABLE t1;
#
# Bug #57030: 'BETWEEN' evaluation is incorrect
#
CREATE TABLE t1(pk INT PRIMARY KEY, i4 INT);
CREATE UNIQUE INDEX i4_uq ON t1(i4);
INSERT INTO t1 VALUES (1,10), (2,20), (3,30);
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const i4_uq i4_uq 5 const 1
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10;
pk i4
1 10
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const i4_uq i4_uq 5 const 1
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4;
pk i4
1 10
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND i4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range i4_uq i4_uq 5 NULL 3 Using where
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND i4;
pk i4
1 10
2 20
3 30
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range i4_uq i4_uq 5 NULL 1 Using where
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10;
pk i4
1 10
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10;
pk i4
1 10
2 20
3 30
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11;
pk i4
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0;
pk i4
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0;
pk i4
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 99999999999999999;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range i4_uq i4_uq 5 NULL 2 Using where
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 99999999999999999;
pk i4
1 10
2 20
3 30
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30;
pk i4
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range i4_uq i4_uq 5 NULL 1 Using where
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20';
pk i4
1 10
2 20
EXPLAIN
SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL i4_uq NULL NULL NULL 3
1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.i4 1 Using where
SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4;
pk i4 pk i4
EXPLAIN
SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL i4_uq NULL NULL NULL 3
1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.i4 1 Using where
SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk;
pk i4 pk i4
DROP TABLE t1;
End of 5.1 tests
......@@ -1325,4 +1325,71 @@ SELECT * FROM t1 WHERE 2 NOT BETWEEN c_notkey AND c_key;
DROP TABLE t1;
--echo #
--echo # Bug #57030: 'BETWEEN' evaluation is incorrect
--echo #
# Test some BETWEEN predicates which does *not* follow the
# 'normal' pattern of <field> BETWEEN <low const> AND <high const>
CREATE TABLE t1(pk INT PRIMARY KEY, i4 INT);
CREATE UNIQUE INDEX i4_uq ON t1(i4);
INSERT INTO t1 VALUES (1,10), (2,20), (3,30);
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10;
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 10;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4;
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND i4;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND i4;
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND i4;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10;
SELECT * FROM t1 WHERE 10 BETWEEN i4 AND 10;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10;
SELECT * FROM t1 WHERE 10 BETWEEN 10 AND 10;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11;
SELECT * FROM t1 WHERE 10 BETWEEN 11 AND 11;
EXPLAIN
SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0;
SELECT * FROM t1 WHERE 10 BETWEEN 100 AND 0;
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0;
SELECT * FROM t1 WHERE i4 BETWEEN 100 AND 0;
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 99999999999999999;
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND 99999999999999999;
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30;
SELECT * FROM t1 WHERE i4 BETWEEN 999999999999999 AND 30;
EXPLAIN
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20';
SELECT * FROM t1 WHERE i4 BETWEEN 10 AND '20';
#Should detect the EQ_REF 't2.pk=t1.i4'
EXPLAIN
SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4;
SELECT * FROM t1, t1 as t2 WHERE t2.pk BETWEEN t1.i4 AND t1.i4;
EXPLAIN
SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk;
SELECT * FROM t1, t1 as t2 WHERE t1.i4 BETWEEN t2.pk AND t2.pk;
DROP TABLE t1;
--echo End of 5.1 tests
......@@ -3349,26 +3349,7 @@ add_key_field(KEY_FIELD **key_fields,uint and_level, Item_func *cond,
eq_func is NEVER true when num_values > 1
*/
if (!eq_func)
{
/*
Additional optimization: if we're processing
"t.key BETWEEN c1 AND c1" then proceed as if we were processing
"t.key = c1".
TODO: This is a very limited fix. A more generic fix is possible.
There are 2 options:
A) Make equality propagation code be able to handle BETWEEN
(including cases like t1.key BETWEEN t2.key AND t3.key)
B) Make range optimizer to infer additional "t.key = c" equalities
and use them in equality propagation process (see details in
OptimizerKBAndTodo)
*/
if ((cond->functype() != Item_func::BETWEEN) ||
((Item_func_between*) cond)->negated ||
!value[0]->eq(value[1], field->binary()))
return;
eq_func= TRUE;
}
if (field->result_type() == STRING_RESULT)
{
if ((*value)->result_type() != STRING_RESULT)
......@@ -3564,8 +3545,64 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
case Item_func::OPTIMIZE_KEY:
{
Item **values;
// BETWEEN, IN, NE
if (is_local_field (cond_func->key_item()) &&
/*
Build list of possible keys for 'a BETWEEN low AND high'.
It is handled similar to the equivalent condition
'a >= low AND a <= high':
*/
if (cond_func->functype() == Item_func::BETWEEN)
{
Item_field *field_item;
bool equal_func= FALSE;
uint num_values= 2;
values= cond_func->arguments();
bool binary_cmp= (values[0]->real_item()->type() == Item::FIELD_ITEM)
? ((Item_field*)values[0]->real_item())->field->binary()
: TRUE;
/*
Additional optimization: If 'low = high':
Handle as if the condition was "t.key = low".
*/
if (!((Item_func_between*)cond_func)->negated &&
values[1]->eq(values[2], binary_cmp))
{
equal_func= TRUE;
num_values= 1;
}
/*
Append keys for 'field <cmp> value[]' if the
condition is of the form::
'<field> BETWEEN value[1] AND value[2]'
*/
if (is_local_field (values[0]))
{
field_item= (Item_field *) (values[0]->real_item());
add_key_equal_fields(key_fields, *and_level, cond_func,
field_item, equal_func, &values[1],
num_values, usable_tables, sargables);
}
/*
Append keys for 'value[0] <cmp> field' if the
condition is of the form:
'value[0] BETWEEN field1 AND field2'
*/
for (uint i= 1; i <= num_values; i++)
{
if (is_local_field (values[i]))
{
field_item= (Item_field *) (values[i]->real_item());
add_key_equal_fields(key_fields, *and_level, cond_func,
field_item, equal_func, values,
1, usable_tables, sargables);
}
}
} // if ( ... Item_func::BETWEEN)
// IN, NE
else if (is_local_field (cond_func->key_item()) &&
!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
{
values= cond_func->arguments()+1;
......@@ -3580,21 +3617,6 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
cond_func->argument_count()-1,
usable_tables, sargables);
}
if (cond_func->functype() == Item_func::BETWEEN)
{
values= cond_func->arguments();
for (uint i= 1 ; i < cond_func->argument_count() ; i++)
{
Item_field *field_item;
if (is_local_field (cond_func->arguments()[i]))
{
field_item= (Item_field *) (cond_func->arguments()[i]->real_item());
add_key_equal_fields(key_fields, *and_level, cond_func,
field_item, 0, values, 1, usable_tables,
sargables);
}
}
}
break;
}
case Item_func::OPTIMIZE_OP:
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment