MDEV-12568 Add Type_handler::subquery_type_allows_materialization()

sql/item.cc

@@ -9711,9 +9711,8 @@ Item_cache_temporal::Item_cache_temporal(THD *thd,
                                          enum_field_types field_type_arg):
   Item_cache_int(thd, field_type_arg)
 {
-  if (mysql_type_to_time_type(Item_cache_temporal::field_type()) ==
-                              MYSQL_TIMESTAMP_ERROR)
-    set_handler_by_field_type(MYSQL_TYPE_DATETIME);
+  if (mysql_timestamp_type() == MYSQL_TIMESTAMP_ERROR)
+    set_handler(&type_handler_datetime2);
 }
 
 
@@ -9821,7 +9820,7 @@ bool Item_cache_temporal::get_date(MYSQL_TIME *ltime, ulonglong fuzzydate)
   }
 
   unpack_time(value, ltime);
-  ltime->time_type= mysql_type_to_time_type(field_type());
+  ltime->time_type= mysql_timestamp_type();
   if (ltime->time_type == MYSQL_TIMESTAMP_TIME)
   {
     ltime->hour+= (ltime->month*32+ltime->day)*24;

sql/item_func.cc

@@ -890,7 +890,7 @@ String *Item_func_hybrid_field_type::val_str_from_date_op(String *str)
   if (date_op_with_null_check(&ltime) ||
       (null_value= str->alloc(MAX_DATE_STRING_REP_LENGTH)))
     return (String *) 0;
-  ltime.time_type= mysql_type_to_time_type(field_type());
+  ltime.time_type= mysql_timestamp_type();
   str->length(my_TIME_to_str(&ltime, const_cast<char*>(str->ptr()), decimals));
   str->set_charset(&my_charset_bin);
   DBUG_ASSERT(!null_value);
@@ -902,7 +902,7 @@ double Item_func_hybrid_field_type::val_real_from_date_op()
   MYSQL_TIME ltime;
   if (date_op_with_null_check(&ltime))
     return 0;
-  ltime.time_type= mysql_type_to_time_type(field_type());
+  ltime.time_type= mysql_timestamp_type();
   return TIME_to_double(&ltime);
 }
 longlong Item_func_hybrid_field_type::val_int_from_date_op()
@@ -910,7 +910,7 @@ longlong Item_func_hybrid_field_type::val_int_from_date_op()
   MYSQL_TIME ltime;
   if (date_op_with_null_check(&ltime))
     return 0;
-  ltime.time_type= mysql_type_to_time_type(field_type());
+  ltime.time_type= mysql_timestamp_type();
   return TIME_to_ulonglong(&ltime);
 }
 
@@ -923,7 +923,7 @@ Item_func_hybrid_field_type::val_decimal_from_date_op(my_decimal *dec)
     my_decimal_set_zero(dec);
     return 0;
   }
-  ltime.time_type= mysql_type_to_time_type(field_type());
+  ltime.time_type= mysql_timestamp_type();
   return date2my_decimal(&ltime, dec);
 }
 

sql/item_timefunc.cc

@@ -1532,7 +1532,7 @@ String *Item_temporal_hybrid_func::val_str_ascii(String *str)
   /* Check that the returned timestamp type matches to the function type */
   DBUG_ASSERT(field_type() == MYSQL_TYPE_STRING ||
               ltime.time_type == MYSQL_TIMESTAMP_NONE ||
-              mysql_type_to_time_type(field_type()) == ltime.time_type);
+              ltime.time_type == mysql_timestamp_type());
   return str;
 }
 
@@ -3226,7 +3226,7 @@ void Item_func_str_to_date::fix_length_and_dec()
       }
     }
   }
-  cached_timestamp_type= mysql_type_to_time_type(field_type());
+  cached_timestamp_type= mysql_timestamp_type();
 }
 
 

sql/opt_subselect.cc

@@ -843,34 +843,9 @@ bool subquery_types_allow_materialization(Item_in_subselect *in_subs)
     all_are_fields &= (outer->real_item()->type() == Item::FIELD_ITEM && 
                        inner->real_item()->type() == Item::FIELD_ITEM);
     total_key_length += inner->max_length;
-    if (outer->cmp_type() != inner->cmp_type())
+    if (!inner->type_handler()->subquery_type_allows_materialization(inner,
+                                                                     outer))
       DBUG_RETURN(FALSE);
-    switch (outer->cmp_type()) {
-    case STRING_RESULT:
-      if (!(outer->collation.collation == inner->collation.collation))
-        DBUG_RETURN(FALSE);
-      // Materialization does not work with BLOB columns
-      if (inner->field_type() == MYSQL_TYPE_BLOB || 
-          inner->field_type() == MYSQL_TYPE_GEOMETRY)
-        DBUG_RETURN(FALSE);
-      /* 
-        Materialization also is unable to work when create_tmp_table() will
-        create a blob column because item->max_length is too big.
-        The following check is copied from Item::make_string_field():
-      */ 
-      if (inner->too_big_for_varchar())
-      {
-        DBUG_RETURN(FALSE);
-      }
-      break;
-    case TIME_RESULT:
-      if (mysql_type_to_time_type(outer->field_type()) !=
-          mysql_type_to_time_type(inner->field_type()))
-        DBUG_RETURN(FALSE);
-    default:
-      /* suitable for materialization */
-      break;
-    }
   }
 
   /*

sql/sql_type.cc

@@ -3187,3 +3187,57 @@ uint Type_handler_string_result::Item_temporal_precision(Item *item,
 }
 
 /***************************************************************************/
+
+bool Type_handler_real_result::
+       subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+{
+  DBUG_ASSERT(inner->cmp_type() == REAL_RESULT);
+  return outer->cmp_type() == REAL_RESULT;
+}
+
+
+bool Type_handler_int_result::
+       subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+{
+  DBUG_ASSERT(inner->cmp_type() == INT_RESULT);
+  return outer->cmp_type() == INT_RESULT;
+}
+
+
+bool Type_handler_decimal_result::
+       subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+{
+  DBUG_ASSERT(inner->cmp_type() == DECIMAL_RESULT);
+  return outer->cmp_type() == DECIMAL_RESULT;
+}
+
+
+bool Type_handler_string_result::
+       subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+{
+  DBUG_ASSERT(inner->cmp_type() == STRING_RESULT);
+  return outer->cmp_type() == STRING_RESULT &&
+         outer->collation.collation == inner->collation.collation &&
+         /*
+           Materialization also is unable to work when create_tmp_table() will
+           create a blob column because item->max_length is too big.
+           The following test is copied from Item::make_string_field():
+         */
+         !inner->too_big_for_varchar();
+}
+
+
+bool Type_handler_temporal_result::
+       subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+{
+  DBUG_ASSERT(inner->cmp_type() == TIME_RESULT);
+  return mysql_timestamp_type() ==
+         outer->type_handler()->mysql_timestamp_type();
+}
+
+/***************************************************************************/

sql/sql_type.h

@@ -367,6 +367,10 @@ class Type_handler
   virtual enum_field_types real_field_type() const { return field_type(); }
   virtual Item_result result_type() const= 0;
   virtual Item_result cmp_type() const= 0;
+  virtual enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return MYSQL_TIMESTAMP_ERROR;
+  }
   /**
     Prepared statement long data:
     Check whether this parameter data type is compatible with long data.
@@ -480,6 +484,9 @@ class Type_handler
                                Item *target_expr, Item *target_value,
                                Item_bool_func2 *source,
                                Item *source_expr, Item *source_const) const= 0;
+  virtual bool
+  subquery_type_allows_materialization(const Item *inner,
+                                       const Item *outer) const= 0;
   virtual Item_cache *Item_get_cache(THD *thd, const Item *item) const= 0;
   virtual bool set_comparator_func(Arg_comparator *cmp) const= 0;
   virtual bool Item_hybrid_func_fix_attributes(THD *thd, Item_hybrid_func *func,
@@ -605,6 +612,12 @@ class Type_handler_row: public Type_handler
     return ROW_RESULT;
   }
   const Type_handler *type_handler_for_comparison() const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+  {
+    DBUG_ASSERT(0);
+    return false;
+  }
   Field *make_num_distinct_aggregator_field(MEM_ROOT *, const Item *) const
   {
     DBUG_ASSERT(0);
@@ -834,6 +847,8 @@ class Type_handler_real_result: public Type_handler_numeric
   Item_result cmp_type() const { return REAL_RESULT; }
   virtual ~Type_handler_real_result() {}
   const Type_handler *type_handler_for_comparison() const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const;
   void make_sort_key(uchar *to, Item *item, const SORT_FIELD_ATTR *sort_field,
                      Sort_param *param) const;
   void sortlength(THD *thd,
@@ -889,6 +904,8 @@ class Type_handler_decimal_result: public Type_handler_numeric
   Item_result cmp_type() const { return DECIMAL_RESULT; }
   virtual ~Type_handler_decimal_result() {};
   const Type_handler *type_handler_for_comparison() const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const;
   Field *make_num_distinct_aggregator_field(MEM_ROOT *, const Item *) const;
   void make_sort_key(uchar *to, Item *item, const SORT_FIELD_ATTR *sort_field,
                      Sort_param *param) const;
@@ -943,6 +960,8 @@ class Type_handler_int_result: public Type_handler_numeric
   Item_result cmp_type() const { return INT_RESULT; }
   virtual ~Type_handler_int_result() {}
   const Type_handler *type_handler_for_comparison() const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const;
   Field *make_num_distinct_aggregator_field(MEM_ROOT *, const Item *) const;
   void make_sort_key(uchar *to, Item *item, const SORT_FIELD_ATTR *sort_field,
                      Sort_param *param) const;
@@ -1005,6 +1024,8 @@ class Type_handler_temporal_result: public Type_handler
                                    Item *target_expr, Item *target_value,
                                    Item_bool_func2 *source,
                                    Item *source_expr, Item *source_const) const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const;
   bool set_comparator_func(Arg_comparator *cmp) const;
   bool Item_sum_hybrid_fix_length_and_dec(Item_sum_hybrid *func) const;
@@ -1081,6 +1102,8 @@ class Type_handler_string_result: public Type_handler
                                    Item *target_expr, Item *target_value,
                                    Item_bool_func2 *source,
                                    Item *source_expr, Item *source_const) const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const;
   bool set_comparator_func(Arg_comparator *cmp) const;
   bool Item_hybrid_func_fix_attributes(THD *thd, Item_hybrid_func *func,
@@ -1278,6 +1301,10 @@ class Type_handler_time_common: public Type_handler_temporal_result
   virtual ~Type_handler_time_common() { }
   const Name name() const { return m_name_time; }
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
+  enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return MYSQL_TIMESTAMP_TIME;
+  }
   const Type_handler *type_handler_for_comparison() const;
   int Item_save_in_field(Item *item, Field *field, bool no_conversions) const;
   String *print_item_value(THD *thd, Item *item, String *str) const;
@@ -1325,6 +1352,10 @@ class Type_handler_date_common: public Type_handler_temporal_with_date
   virtual ~Type_handler_date_common() {}
   const Name name() const { return m_name_date; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return MYSQL_TIMESTAMP_DATE;
+  }
   String *print_item_value(THD *thd, Item *item, String *str) const;
   bool Item_hybrid_func_fix_attributes(THD *thd, Item_hybrid_func *func,
                                        Item **items, uint nitems) const;
@@ -1355,6 +1386,10 @@ class Type_handler_datetime_common: public Type_handler_temporal_with_date
   virtual ~Type_handler_datetime_common() {}
   const Name name() const { return m_name_datetime; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
+  enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return MYSQL_TIMESTAMP_DATETIME;
+  }
   String *print_item_value(THD *thd, Item *item, String *str) const;
   bool Item_hybrid_func_fix_attributes(THD *thd, Item_hybrid_func *func,
                                        Item **items, uint nitems) const;
@@ -1387,6 +1422,10 @@ class Type_handler_timestamp_common: public Type_handler_temporal_with_date
   virtual ~Type_handler_timestamp_common() {}
   const Name name() const { return m_name_timestamp; }
   enum_field_types field_type() const { return MYSQL_TYPE_TIMESTAMP; }
+  enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return MYSQL_TIMESTAMP_DATETIME;
+  }
   String *print_item_value(THD *thd, Item *item, String *str) const;
   bool Item_hybrid_func_fix_attributes(THD *thd, Item_hybrid_func *func,
                                        Item **items, uint nitems) const;
@@ -1480,6 +1519,11 @@ class Type_handler_blob_common: public Type_handler_string_result
 {
 public:
   virtual ~Type_handler_blob_common() { }
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+  {
+    return false; // Materialization does not work with BLOB columns
+  }
   bool is_param_long_data_type() const { return true; }
 };
 
@@ -1542,6 +1586,11 @@ class Type_handler_geometry: public Type_handler_string_result
   enum_field_types field_type() const { return MYSQL_TYPE_GEOMETRY; }
   bool is_param_long_data_type() const { return true; }
   const Type_handler *type_handler_for_comparison() const;
+  bool subquery_type_allows_materialization(const Item *inner,
+                                            const Item *outer) const
+  {
+    return false; // Materialization does not work with GEOMETRY columns
+  }
   Field *make_conversion_table_field(TABLE *, uint metadata,
                                      const Field *target) const;
   bool is_traditional_type() const
@@ -1628,6 +1677,10 @@ class Type_handler_hybrid_field_type
   }
   Item_result result_type() const { return m_type_handler->result_type(); }
   Item_result cmp_type() const { return m_type_handler->cmp_type(); }
+  enum_mysql_timestamp_type mysql_timestamp_type() const
+  {
+    return m_type_handler->mysql_timestamp_type();
+  }
   void set_handler(const Type_handler *other)
   {
     m_type_handler= other;