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.

1 files changed, 67 insertions, 0 deletions

diff --git a/mysql-test/t/range.test b/mysql-test/t/range.test
index 0ad3d3e8504..6c9320b708a 100644
--- a/mysql-test/t/range.test
+++ b/mysql-test/t/range.test
@@ -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