Hi Ole,
This fix is incorrect. Anyway, IMO, the another your fix is better, with some
additions.
Regards, Evgen.
On 12/03/10 17:23, Ole John Aske wrote:
> #At file:///net/fimafeng09/export/home/tmp/oleja/mysql/mysql-5.1/ based on
> revid:georgi.kodinov@stripped
>
> 3477 Ole John Aske 2010-12-03
> 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 the 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 uses the 'num_values' argument to detect the cases where the BETWEEN
> should not be interpreted as a BETWEEN anymore. if 'num_values< 2' it has
> logicaly
> been transformed to a GE / LE.
>
> modified:
> mysql-test/r/range.result
> mysql-test/t/range.test
> sql/sql_select.cc
> === modified file 'mysql-test/r/range.result'
> --- a/mysql-test/r/range.result 2010-08-24 15:51:32 +0000
> +++ b/mysql-test/r/range.result 2010-12-03 14:23:13 +0000
> @@ -1666,4 +1666,91 @@ 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 range i4_uq i4_uq 5 NULL 1 Using where
> +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
> +DROP TABLE t1;
> End of 5.1 tests
>
> === modified file 'mysql-test/t/range.test'
> --- a/mysql-test/t/range.test 2010-08-24 15:51:32 +0000
> +++ b/mysql-test/t/range.test 2010-12-03 14:23:13 +0000
> @@ -1325,4 +1325,63 @@ SELECT * FROM t1 WHERE 2 NOT BETWEEN c_n
>
> 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';
> +
> +
> +DROP TABLE t1;
> +
> --echo End of 5.1 tests
>
> === modified file 'sql/sql_select.cc'
> --- a/sql/sql_select.cc 2010-10-29 08:23:06 +0000
> +++ b/sql/sql_select.cc 2010-12-03 14:23:13 +0000
> @@ -3363,6 +3363,7 @@ add_key_field(KEY_FIELD **key_fields,uin
> */
> if ((cond->functype() != Item_func::BETWEEN) ||
> ((Item_func_between*) cond)->negated ||
> + num_values< 2 ||
> !value[0]->eq(value[1], field->binary()))
> return;
> eq_func= TRUE;
The actual bug here is 2 typos, correct check should be
!value[1]->eq(value[2], field->binary())
The comment above 'if' confirms this and in your another fix you also compare value[1] and
value[2].
