MDEV-8330 Get rid of Item_func::select_optimize() and Item_func::optimize_type

sql/item_cmpfunc.cc

@@ -4831,22 +4831,21 @@ longlong Item_func_like::val_int()
   We can optimize a where if first character isn't a wildcard
 */
 
-Item_func::optimize_type Item_func_like::select_optimize() const
+bool Item_func_like::with_sargable_pattern() const
 {
   if (!args[1]->const_item() || args[1]->is_expensive())
-    return OPTIMIZE_NONE;
+    return false;
 
   String* res2= args[1]->val_str((String *) &cmp_value2);
   if (!res2)
-    return OPTIMIZE_NONE;
+    return false;
 
   if (!res2->length()) // Can optimize empty wildcard: column LIKE ''
-    return OPTIMIZE_OP;
+    return true;
 
   DBUG_ASSERT(res2->ptr());
   char first= res2->ptr()[0];
-  return (first == wild_many || first == wild_one) ?
-    OPTIMIZE_NONE : OPTIMIZE_OP;
+  return first != wild_many && first != wild_one;
 }
 
 

sql/item_cmpfunc.h

@@ -290,14 +290,14 @@ public:
 */
 class Item_bool_func2 :public Item_bool_func
 {                                              /* Bool with 2 string args */
+  bool have_rev_func() const { return rev_functype() != UNKNOWN_FUNC; }
 public:
   Item_bool_func2(Item *a,Item *b)
     :Item_bool_func(a,b) { }
-  optimize_type select_optimize() const { return OPTIMIZE_OP; }
   virtual enum Functype rev_functype() const { return UNKNOWN_FUNC; }
-  bool have_rev_func() const { return rev_functype() != UNKNOWN_FUNC; }
 
   bool is_null() { return MY_TEST(args[0]->is_null() || args[1]->is_null()); }
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   COND *remove_eq_conds(THD *thd, Item::cond_result *cond_value,
                         bool top_level);
   bool count_sargable_conds(uchar *arg);
@@ -592,7 +592,6 @@ public:
   longlong val_int();
   enum Functype functype() const { return NE_FUNC; }
   cond_result eq_cmp_result() const { return COND_FALSE; }
-  optimize_type select_optimize() const { return OPTIMIZE_KEY; } 
   const char *func_name() const { return "<>"; }
   Item *negated_item();
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
@@ -643,7 +642,6 @@ public:
   Item_func_between(Item *a, Item *b, Item *c)
     :Item_func_opt_neg(a, b, c), compare_as_dates(FALSE) { }
   longlong val_int();
-  optimize_type select_optimize() const { return OPTIMIZE_KEY; }
   enum Functype functype() const   { return BETWEEN; }
   const char *func_name() const { return "between"; }
   bool fix_fields(THD *, Item **);
@@ -1334,8 +1332,6 @@ public:
     }
     DBUG_VOID_RETURN;
   }
-  optimize_type select_optimize() const
-    { return OPTIMIZE_KEY; }
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                       table_map usable_tables, SARGABLE_PARAM **sargables);
   SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
@@ -1383,9 +1379,9 @@ class Item_func_null_predicate :public Item_bool_func
 {
 public:
   Item_func_null_predicate(Item *a) :Item_bool_func(a) { }
-  optimize_type select_optimize() const { return OPTIMIZE_NULL; }
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                       table_map usable_tables, SARGABLE_PARAM **sargables);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   CHARSET_INFO *compare_collation() const
   { return args[0]->collation.collation; }
   void fix_length_and_dec() { decimals=0; max_length=1; maybe_null=0; }
@@ -1495,6 +1491,7 @@ class Item_func_like :public Item_bool_func2
 
   DTCollation cmp_collation;
   String cmp_value1, cmp_value2;
+  bool with_sargable_pattern() const;
 public:
   int escape;
 
@@ -1508,7 +1505,6 @@ public:
   {
     Item_func::print_op(str, query_type);
   }
-  optimize_type select_optimize() const;
   CHARSET_INFO *compare_collation() const
   { return cmp_collation.collation; }
   cond_result eq_cmp_result() const
@@ -1548,6 +1544,12 @@ public:
   }
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                       table_map usable_tables, SARGABLE_PARAM **sargables);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr)
+  {
+    return with_sargable_pattern() ?
+           Item_bool_func2::get_mm_tree(param, cond_ptr) :
+           Item_func::get_mm_tree(param, cond_ptr);
+  }
   const char *func_name() const { return "like"; }
   bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec()
@@ -1930,7 +1932,6 @@ public:
   enum Functype functype() const { return MULT_EQUAL_FUNC; }
   longlong val_int(); 
   const char *func_name() const { return "multiple equal"; }
-  optimize_type select_optimize() const { return OPTIMIZE_EQUAL; }
   void sort(Item_field_cmpfunc compare, void *arg);
   void fix_length_and_dec();
   bool fix_fields(THD *thd, Item **ref);

sql/item_func.h

@@ -60,8 +60,6 @@ public:
                   SUSERVAR_FUNC, GUSERVAR_FUNC, COLLATE_FUNC,
                   EXTRACT_FUNC, CHAR_TYPECAST_FUNC, FUNC_SP, UDF_FUNC,
                   NEG_FUNC, GSYSVAR_FUNC, DYNCOL_FUNC };
-  enum optimize_type { OPTIMIZE_NONE,OPTIMIZE_KEY,OPTIMIZE_OP, OPTIMIZE_NULL,
-                       OPTIMIZE_EQUAL };
   enum Type type() const { return FUNC_ITEM; }
   virtual enum Functype functype() const   { return UNKNOWN_FUNC; }
   Item_func(void):
@@ -136,8 +134,6 @@ public:
                           COND_EQUAL **cond_equal_ref);
   SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   bool eq(const Item *item, bool binary_cmp) const;
-  virtual optimize_type select_optimize() const { return OPTIMIZE_NONE; }
-  virtual bool have_rev_func() const { return 0; }
   virtual Item *key_item() const { return args[0]; }
   virtual bool const_item() const { return const_item_cache; }
   void set_arguments(List<Item> &list)

sql/opt_range.cc

@@ -8203,19 +8203,41 @@ SEL_TREE *Item_equal::get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr)
 SEL_TREE *Item_func::get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr)
 {
   DBUG_ENTER("Item_func::get_mm_tree");
+  DBUG_RETURN(const_item() ? get_mm_tree_for_const(param, this) : NULL);
+}
+
+
+SEL_TREE *Item_func_null_predicate::get_mm_tree(RANGE_OPT_PARAM *param,
+                                                Item **cond_ptr)
+{
+  DBUG_ENTER("Item_func_null_predicate::get_mm_tree");
   if (const_item())
     DBUG_RETURN(get_mm_tree_for_const(param, this));
+  param->cond= this;
+  if (args[0]->real_item()->type() == Item::FIELD_ITEM)
+  {
+    Item_field *field_item= (Item_field*) args[0]->real_item();
+    if (!field_item->const_item())
+      DBUG_RETURN(get_full_func_mm_tree(param, this, field_item, NULL, false));
+  }
+  DBUG_RETURN(NULL);
+}
 
-  if (select_optimize() == Item_func::OPTIMIZE_NONE)
-    DBUG_RETURN(0);
+
+SEL_TREE *Item_bool_func2::get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr)
+{
+  DBUG_ENTER("Item_bool_func2::get_mm_tree");
+  if (const_item())
+    DBUG_RETURN(get_mm_tree_for_const(param, this));
 
   param->cond= this;
 
   SEL_TREE *ftree= 0;
+  DBUG_ASSERT(arg_count == 2);
   if (arguments()[0]->real_item()->type() == Item::FIELD_ITEM)
   {
     Item_field *field_item= (Item_field*) (arguments()[0]->real_item());
-    Item *value= arg_count > 1 ? arguments()[1] : NULL;
+    Item *value= arguments()[1];
     if (value && value->is_expensive())
       DBUG_RETURN(0);
     if (!arguments()[0]->real_item()->const_item())

sql/sql_select.cc

@@ -4759,8 +4759,7 @@ Item_func_like::add_key_fields(JOIN *join, KEY_FIELD **key_fields,
                                uint *and_level, table_map usable_tables,
                                SARGABLE_PARAM **sargables)
 {
-  if (is_local_field(args[0]) &&
-      Item_func_like::select_optimize() == OPTIMIZE_OP)
+  if (is_local_field(args[0]) && with_sargable_pattern())
   {
     /*
       SELECT * FROM t1 WHERE field LIKE const_pattern