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

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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.
This commit is contained in:
Ole John Aske
2011-02-01 13:20:16 +01:00
parent b6b7be691c
commit c8de3bba8e
3 changed files with 228 additions and 38 deletions
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101
mysql-test/r/range.result
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@@ -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