MDEV-8599 "WHERE varchar_field LIKE temporal_const" does not use range optimizer

Author: Alexander Barkov

mysql-test/r/func_like.result

@@ -227,5 +227,30 @@ Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` = 10.0) and (`test`.`t1`.`a` like 10.00))
 DROP TABLE t1;
 #
+# MDEV-8599 "WHERE varchar_field LIKE temporal_const" does not use range optimizer
+#
+CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('00:00:00');
+INSERT INTO t1 VALUES ('00:00:01');
+INSERT INTO t1 VALUES ('00:00:02');
+INSERT INTO t1 VALUES ('00:00:03');
+INSERT INTO t1 VALUES ('00:00:04');
+INSERT INTO t1 VALUES ('00:00:05');
+INSERT INTO t1 VALUES ('00:00:06');
+INSERT INTO t1 VALUES ('00:00:07');
+EXPLAIN SELECT * FROM t1 WHERE a LIKE '00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	a	a	13	NULL	1	Using where; Using index
+EXPLAIN SELECT * FROM t1 WHERE a LIKE TIME'00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	a	a	13	NULL	1	Using where; Using index
+SELECT * FROM t1 WHERE a LIKE '00:00:00';
+a
+00:00:00
+SELECT * FROM t1 WHERE a LIKE TIME'00:00:00';
+a
+00:00:00
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #

mysql-test/t/func_like.test

@@ -163,6 +163,25 @@ SELECT * FROM t1 WHERE a=10.0 AND a LIKE 10.00;
 EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10.0 AND a LIKE 10.00;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-8599 "WHERE varchar_field LIKE temporal_const" does not use range optimizer
+--echo #
+CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('00:00:00');
+INSERT INTO t1 VALUES ('00:00:01');
+INSERT INTO t1 VALUES ('00:00:02');
+INSERT INTO t1 VALUES ('00:00:03');
+INSERT INTO t1 VALUES ('00:00:04');
+INSERT INTO t1 VALUES ('00:00:05');
+INSERT INTO t1 VALUES ('00:00:06');
+INSERT INTO t1 VALUES ('00:00:07');
+EXPLAIN SELECT * FROM t1 WHERE a LIKE '00:00:00';
+EXPLAIN SELECT * FROM t1 WHERE a LIKE TIME'00:00:00';
+SELECT * FROM t1 WHERE a LIKE '00:00:00';
+SELECT * FROM t1 WHERE a LIKE TIME'00:00:00';
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.1 tests
 --echo #

sql/item_cmpfunc.h

@@ -120,6 +120,10 @@ class Arg_comparator: public Sql_alloc
   friend class Item_func;
 };
 
+
+class SEL_ARG;
+struct KEY_PART;
+
 class Item_bool_func :public Item_int_func
 {
 protected:
@@ -147,6 +151,9 @@ class Item_bool_func :public Item_int_func
   SEL_TREE *get_ne_mm_tree(RANGE_OPT_PARAM *param,
                            Field *field, Item *lt_value, Item *gt_value,
                            Item_result cmp_type);
+  virtual SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field,
+                               KEY_PART *key_part,
+                               Item_func::Functype type, Item *value);
 public:
   Item_bool_func() :Item_int_func() {}
   Item_bool_func(Item *a) :Item_int_func(a) {}
@@ -1437,6 +1444,9 @@ class Item_func_null_predicate :public Item_bool_func
     DBUG_ENTER("Item_func_null_predicate::get_func_mm_tree");
     DBUG_RETURN(get_mm_parts(param, field, functype(), value, cmp_type));
   }
+  SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field,
+                       KEY_PART *key_part,
+                       Item_func::Functype type, Item *value);
 public:
   Item_func_null_predicate(Item *a) :Item_bool_func(a) { }
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
@@ -1552,6 +1562,10 @@ class Item_func_like :public Item_bool_func2
   DTCollation cmp_collation;
   String cmp_value1, cmp_value2;
   bool with_sargable_pattern() const;
+protected:
+  SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field,
+                       KEY_PART *key_part,
+                       Item_func::Functype type, Item *value);
 public:
   int escape;