Initial patch for the implementation of window functions (MDEV-6115):

- All parsing problems look like resolved
- Stub performing name resolution of window functions
in simplest queries has been added.

14 files changed, 767 insertions, 6 deletions

diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index 9b0017c9124..19fbed85737 100644
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -122,7 +122,7 @@ SET (SQL_SOURCE
                sql_profile.cc event_parse_data.cc sql_alter.cc
                sql_signal.cc rpl_handler.cc mdl.cc sql_admin.cc
                transaction.cc sys_vars.cc sql_truncate.cc datadict.cc
-               sql_reload.cc sql_cmd.h item_inetfunc.cc
+               sql_reload.cc sql_cmd.h item_inetfunc.cc 
 
                # added in MariaDB:
                sql_explain.h sql_explain.cc
@@ -137,6 +137,7 @@ SET (SQL_SOURCE
                my_json_writer.cc my_json_writer.h
                rpl_gtid.cc rpl_parallel.cc
                sql_type.cc sql_type.h
+               item_windowfunc.cc sql_window.cc
 	       ${WSREP_SOURCES}
                table_cache.cc encryption.cc
                ${CMAKE_CURRENT_BINARY_DIR}/sql_builtin.cc
diff --git a/sql/item.h b/sql/item.h
index 4051674358e..46d09c247fe 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -628,7 +628,8 @@ public:
   static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); }
   static void operator delete(void *ptr, MEM_ROOT *mem_root) {}
 
-  enum Type {FIELD_ITEM= 0, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM,
+  enum Type {FIELD_ITEM= 0, FUNC_ITEM, SUM_FUNC_ITEM,
+             WINDOW_FUNC_ITEM, STRING_ITEM,
 	     INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM,
 	     COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM,
 	     PROC_ITEM,COND_ITEM, REF_ITEM, FIELD_STD_ITEM,
diff --git a/sql/item_sum.h b/sql/item_sum.h
index 68b034c9213..bf4a1560d42 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -347,7 +347,9 @@ public:
   enum Sumfunctype
   { COUNT_FUNC, COUNT_DISTINCT_FUNC, SUM_FUNC, SUM_DISTINCT_FUNC, AVG_FUNC,
     AVG_DISTINCT_FUNC, MIN_FUNC, MAX_FUNC, STD_FUNC,
-    VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC
+    VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC,
+    ROW_NUMBER_FUNC, RANK_FUNC, DENSE_RANK_FUNC, PERCENT_RANK_FUNC,
+    CUME_DIST_FUNC
   };
 
   Item **ref_by; /* pointer to a ref to the object used to register it */
@@ -712,6 +714,7 @@ public:
 class Item_sum_int :public Item_sum_num
 {
 public:
+  Item_sum_int(THD *thd): Item_sum_num(thd) {}
   Item_sum_int(THD *thd, Item *item_par): Item_sum_num(thd, item_par) {}
   Item_sum_int(THD *thd, List<Item> &list): Item_sum_num(thd, list) {}
   Item_sum_int(THD *thd, Item_sum_int *item) :Item_sum_num(thd, item) {}
@@ -726,7 +729,7 @@ public:
 
 
 class Item_sum_sum :public Item_sum_num,
-                    public Type_handler_hybrid_field_type
+                   public Type_handler_hybrid_field_type 
 {
 protected:
   double sum;
diff --git a/sql/item_windowfunc.cc b/sql/item_windowfunc.cc
new file mode 100644
index 00000000000..273a0831116
--- /dev/null
+++ b/sql/item_windowfunc.cc
@@ -0,0 +1,13 @@
+#include "item_windowfunc.h" 
+
+bool
+Item_window_func::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed == 0);
+  
+  if (window_func->fix_fields(thd, ref))
+    return TRUE;
+
+  fixed= 1;
+  return FALSE;
+}
diff --git a/sql/item_windowfunc.h b/sql/item_windowfunc.h
new file mode 100644
index 00000000000..3653cefaf57
--- /dev/null
+++ b/sql/item_windowfunc.h
@@ -0,0 +1,177 @@
+#ifndef ITEM_WINDOWFUNC_INCLUDED
+#define ITEM_WINDOWFUNC_INCLUDED
+
+#include "my_global.h"
+#include "item.h"
+
+class Window_spec;
+
+
+class Item_sum_row_number: public Item_sum_int
+{
+  longlong count;
+
+  void clear() {}
+  bool add() { return false; }
+  void update_field() {}
+
+ public:
+  Item_sum_row_number(THD *thd)
+    : Item_sum_int(thd),  count(0) {}
+
+  enum Sumfunctype sum_func () const
+  {
+    return ROW_NUMBER_FUNC;
+  }
+
+  const char*func_name() const
+  {
+    return "row_number";
+  }
+  
+};
+
+class Item_sum_rank: public Item_sum_int
+{
+  longlong rank;
+
+  void clear() {}
+  bool add() { return false; }
+  void update_field() {}
+
+ public:
+  Item_sum_rank(THD *thd)
+    : Item_sum_int(thd), rank(0) {}
+
+  enum Sumfunctype sum_func () const
+  {
+    return RANK_FUNC;
+  }
+
+  const char*func_name() const
+  {
+    return "rank";
+  }
+  
+};
+
+class Item_sum_dense_rank: public Item_sum_int
+{
+  longlong dense_rank;
+
+  void clear() {}
+  bool add() { return false; }
+  void update_field() {}
+
+ public:
+  Item_sum_dense_rank(THD *thd)
+    : Item_sum_int(thd), dense_rank(0) {}
+  enum Sumfunctype sum_func () const
+  {
+    return DENSE_RANK_FUNC;
+  }
+
+  const char*func_name() const
+  {
+    return "dense_rank";
+  }
+  
+};
+
+class Item_sum_percent_rank: public Item_sum_num
+{
+  longlong rank;
+  longlong partition_rows;
+
+  void clear() {}
+  bool add() { return false; }
+  void update_field() {}
+
+ public:
+  Item_sum_percent_rank(THD *thd)
+    : Item_sum_num(thd), rank(0), partition_rows(0) {}
+
+  double val_real() { return 0; }
+
+  enum Sumfunctype sum_func () const
+  {
+    return PERCENT_RANK_FUNC;
+  }
+
+  const char*func_name() const
+  {
+    return "percent_rank";
+  }
+  
+  enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+
+};
+
+class Item_sum_cume_dist: public Item_sum_num
+{
+  longlong count;
+  longlong partition_rows;
+
+  void clear() {}
+  bool add() { return false; }
+  void update_field() {}
+
+ public:
+  Item_sum_cume_dist(THD *thd)
+    : Item_sum_num(thd), count(0), partition_rows(0) {}
+
+  double val_real() { return 0; }
+
+  enum Sumfunctype sum_func () const
+  {
+    return CUME_DIST_FUNC;
+  }
+
+  const char*func_name() const
+  {
+    return "cume_dist";
+  }
+
+  enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+ 
+};
+
+
+class Item_window_func : public Item_result_field
+{
+private:
+  Item_sum *window_func;
+  LEX_STRING *window_name;
+  Window_spec *window_spec;
+
+public:
+  Item_window_func(THD *thd, Item_sum *win_func, LEX_STRING *win_name)
+    : Item_result_field(thd), window_func(win_func),
+      window_name(win_name), window_spec(NULL) {}
+
+  Item_window_func(THD *thd, Item_sum *win_func, Window_spec *win_spec)
+    : Item_result_field(thd), window_func(win_func),
+      window_name(NULL), window_spec(win_spec) {}
+
+  enum Item::Type type() const { return Item::WINDOW_FUNC_ITEM; }
+
+  enum_field_types field_type() const { return window_func->field_type(); }
+  
+  double val_real() {  return window_func->val_real(); }
+
+  longlong val_int() { return window_func->val_int(); }
+
+  String* val_str(String* str) { return window_func->val_str(str); }
+
+  my_decimal* val_decimal(my_decimal* dec)
+  { return window_func->val_decimal(dec); }
+
+  void fix_length_and_dec() { }
+
+  const char* func_name() const { return "WF"; }
+
+  bool fix_fields(THD *thd, Item **ref);
+};
+
+
+#endif /* ITEM_WINDOWFUNC_INCLUDED */
diff --git a/sql/lex.h b/sql/lex.h
index 22ff4e6d360..05f0050e4f6 100644
--- a/sql/lex.h
+++ b/sql/lex.h
@@ -221,6 +221,7 @@ static SYMBOL symbols[] = {
   { "EVERY",		SYM(EVERY_SYM)},
   { "EXAMINED",         SYM(EXAMINED_SYM)},
   { "EXCHANGE",         SYM(EXCHANGE_SYM)},
+  { "EXCLUDE",          SYM(EXCLUDE_SYM)},
   { "EXECUTE",		SYM(EXECUTE_SYM)},
   { "EXISTS",		SYM(EXISTS)},
   { "EXIT",             SYM(EXIT_SYM)},
@@ -241,6 +242,7 @@ static SYMBOL symbols[] = {
   { "FLOAT4",		SYM(FLOAT_SYM)},
   { "FLOAT8",		SYM(DOUBLE_SYM)},
   { "FLUSH",		SYM(FLUSH_SYM)},
+  { "FOLLOWING",        SYM(FOLLOWING_SYM)},
   { "FOR",		SYM(FOR_SYM)},
   { "FORCE",		SYM(FORCE_SYM)},
   { "FOREIGN",		SYM(FOREIGN)},
@@ -425,9 +427,11 @@ static SYMBOL symbols[] = {
   { "OPTIONALLY",	SYM(OPTIONALLY)},
   { "OR",		SYM(OR_SYM)},
   { "ORDER",		SYM(ORDER_SYM)},
+  { "OTHERS",           SYM(OTHERS_SYM)},
   { "OUT",              SYM(OUT_SYM)},
   { "OUTER",		SYM(OUTER)},
   { "OUTFILE",		SYM(OUTFILE)},
+  { "OVER",             SYM(OVER_SYM)},
   { "OWNER",		SYM(OWNER_SYM)},
   { "PACK_KEYS",	SYM(PACK_KEYS_SYM)},
   { "PAGE",	        SYM(PAGE_SYM)},
@@ -446,6 +450,7 @@ static SYMBOL symbols[] = {
   { "POINT",		SYM(POINT_SYM)},
   { "POLYGON",		SYM(POLYGON)},
   { "PORT",		SYM(PORT_SYM)},
+  { "PRECEDING",        SYM(PRECEDING_SYM)},
   { "PRECISION",	SYM(PRECISION)},
   { "PREPARE",          SYM(PREPARE_SYM)},
   { "PRESERVE",		SYM(PRESERVE_SYM)},
@@ -601,6 +606,7 @@ static SYMBOL symbols[] = {
   { "TEXT",		SYM(TEXT_SYM)},
   { "THAN",             SYM(THAN_SYM)},
   { "THEN",		SYM(THEN_SYM)},
+  { "TIES",             SYM(TIES_SYM)},
   { "TIME",		SYM(TIME_SYM)},
   { "TIMESTAMP",	SYM(TIMESTAMP)},
   { "TIMESTAMPADD",     SYM(TIMESTAMP_ADD)},
@@ -618,6 +624,7 @@ static SYMBOL symbols[] = {
   { "TRUNCATE",		SYM(TRUNCATE_SYM)},
   { "TYPE",		SYM(TYPE_SYM)},
   { "TYPES",		SYM(TYPES_SYM)},
+  { "UNBOUNDED",        SYM(UNBOUNDED_SYM)},
   { "UNCOMMITTED",	SYM(UNCOMMITTED_SYM)},
   { "UNDEFINED",	SYM(UNDEFINED_SYM)},
   { "UNDO_BUFFER_SIZE",	SYM(UNDO_BUFFER_SIZE_SYM)},
@@ -659,6 +666,7 @@ static SYMBOL symbols[] = {
   { "WHEN",		SYM(WHEN_SYM)},
   { "WHERE",		SYM(WHERE)},
   { "WHILE",            SYM(WHILE_SYM)},
+  { "WINDOW",           SYM(WINDOW_SYM)}, 
   { "WITH",		SYM(WITH)},
   { "WORK",		SYM(WORK_SYM)},
   { "WRAPPER",		SYM(WRAPPER_SYM)},
@@ -681,10 +689,12 @@ static SYMBOL sql_functions[] = {
   { "BIT_XOR",		SYM(BIT_XOR)},
   { "CAST",		SYM(CAST_SYM)},
   { "COUNT",		SYM(COUNT_SYM)},
+  { "CUME_DIST",        SYM(CUME_DIST_SYM)},
   { "CURDATE",		SYM(CURDATE)},
   { "CURTIME",		SYM(CURTIME)},
   { "DATE_ADD",		SYM(DATE_ADD_INTERVAL)},
   { "DATE_SUB",		SYM(DATE_SUB_INTERVAL)},
+  { "DENSE_RANK",       SYM(DENSE_RANK_SYM)},
   { "EXTRACT",		SYM(EXTRACT_SYM)},
   { "GROUP_CONCAT",	SYM(GROUP_CONCAT_SYM)},
   { "MAX",		SYM(MAX_SYM)},
@@ -692,6 +702,9 @@ static SYMBOL sql_functions[] = {
   { "MIN",		SYM(MIN_SYM)},
   { "NOW",		SYM(NOW_SYM)},
   { "POSITION",		SYM(POSITION_SYM)},
+  { "PERCENT_RANK",     SYM(PERCENT_RANK_SYM)},
+  { "RANK",             SYM(RANK_SYM)},
+  { "ROW_NUMBER",       SYM(ROW_NUMBER_SYM)},
   { "SESSION_USER",     SYM(USER)},
   { "STD",		SYM(STD_SYM)},
   { "STDDEV",		SYM(STD_SYM)},
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
index 0afd13eb19b..567be4d5a89 100644
--- a/sql/share/errmsg-utf8.txt
+++ b/sql/share/errmsg-utf8.txt
@@ -7136,3 +7136,14 @@ ER_KILL_QUERY_DENIED_ERROR
         eng "You are not owner of query %lu"
         ger "Sie sind nicht Eigentümer von Abfrage %lu"
         rus "Вы не являетесь владельцем запроса %lu"
+ER_WRONG_WINDOW_SPEC_NAME
+        eng "Window specification with name '%s' is not defined"
+ER_DUP_WINDOW_NAME
+        eng "Multiple window specifications with the same name '%s'"
+ER_PARTITION_LIST_IN_REFERENCING_WINDOW_SPEC
+        eng "Window specification referencing another one '%s' cannot contain partition list"
+ER_ORDER_LIST_IN_REFERENCING_WINDOW_SPEC
+        eng "Referenced window specification '%s' already contains order list"
+ER_WINDOW_FRAME_IN_REFERENCED_WINDOW_SPEC
+        eng "Referenced window specification '%s' cannot contain window frame"
+
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 0a1ea705a63..deeb757bdf3 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -546,6 +546,14 @@ void lex_start(THD *thd)
   lex->stmt_var_list.empty();
   lex->proc_list.elements=0;
 
+  lex->save_group_list.empty();
+  lex->save_order_list.empty();
+  lex->win_ref= NULL;
+  lex->win_frame= NULL;
+  lex->frame_top_bound= NULL;
+  lex->frame_bottom_bound= NULL;
+  lex->win_spec= NULL;
+
   lex->is_lex_started= TRUE;
   DBUG_VOID_RETURN;
 }
@@ -1926,6 +1934,7 @@ void st_select_lex::init_query()
   select_list_tables= 0;
   m_non_agg_field_used= false;
   m_agg_func_used= false;
+  window_specs.empty();
 }
 
 void st_select_lex::init_select()
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index e87fcb8cd22..29271bc3e12 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -28,6 +28,7 @@
 #include "mem_root_array.h"
 #include "sql_cmd.h"
 #include "sql_alter.h"                // Alter_info
+#include "sql_window.h"
 
 /* YACC and LEX Definitions */
 
@@ -1070,6 +1071,17 @@ public:
   void set_non_agg_field_used(bool val) { m_non_agg_field_used= val; }
   void set_agg_func_used(bool val)      { m_agg_func_used= val; }
 
+  List<Window_spec> window_specs;
+  void prepare_add_window_spec(THD *thd);
+  bool add_window_def(THD *thd, LEX_STRING *win_name, LEX_STRING *win_ref,
+                      SQL_I_List<ORDER> win_partition_list,
+                      SQL_I_List<ORDER> win_order_list,
+                      Window_frame *win_frame);
+  bool add_window_spec(THD *thd, LEX_STRING *win_ref,
+                       SQL_I_List<ORDER> win_partition_list,
+                       SQL_I_List<ORDER> win_order_list,
+                       Window_frame *win_frame);
+
 private:
   bool m_non_agg_field_used;
   bool m_agg_func_used;
@@ -2706,6 +2718,14 @@ public:
   }
 
 
+  SQL_I_List<ORDER> save_group_list;
+  SQL_I_List<ORDER> save_order_list;
+  LEX_STRING *win_ref;
+  Window_frame *win_frame;
+  Window_frame_bound *frame_top_bound;
+  Window_frame_bound *frame_bottom_bound;
+  Window_spec *win_spec;
+
   inline void free_set_stmt_mem_root()
   {
     DBUG_ASSERT(!is_arena_for_set_stmt());
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 6c99873cef3..6bd1c9b639b 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -7816,6 +7816,53 @@ TABLE_LIST *st_select_lex::convert_right_join()
   DBUG_RETURN(tab1);
 }
 
+
+void st_select_lex::prepare_add_window_spec(THD *thd)
+{
+  LEX *lex= thd->lex;
+  lex->save_group_list= group_list;
+  lex->save_order_list= order_list;
+  lex->win_ref= NULL;
+  lex->win_frame= NULL;
+  lex->frame_top_bound= NULL;
+  lex->frame_bottom_bound= NULL;
+  group_list.empty();
+  order_list.empty();
+}
+
+bool st_select_lex::add_window_def(THD *thd,
+                                   LEX_STRING *win_name,
+                                   LEX_STRING *win_ref,
+                                   SQL_I_List<ORDER> win_partition_list,
+                                   SQL_I_List<ORDER> win_order_list,
+                                   Window_frame *win_frame)
+{
+  Window_def *win_def= new (thd->mem_root) Window_def(win_name,
+                                                      win_ref,
+                                                      win_partition_list,
+                                                      win_order_list,
+                                                      win_frame);
+  group_list= thd->lex->save_group_list;
+  order_list= thd->lex->save_order_list;
+  return (win_def == NULL || window_specs.push_back(win_def));
+}
+
+bool st_select_lex::add_window_spec(THD *thd, 
+                                    LEX_STRING *win_ref,
+                                    SQL_I_List<ORDER> win_partition_list,
+                                    SQL_I_List<ORDER> win_order_list,
+                                    Window_frame *win_frame)
+{
+  Window_spec *win_spec= new (thd->mem_root) Window_spec(win_ref,
+                                                         win_partition_list,
+                                                         win_order_list,
+                                                         win_frame);
+  group_list= thd->lex->save_group_list;
+  order_list= thd->lex->save_order_list;
+  thd->lex->win_spec= win_spec;
+  return (win_spec == NULL || window_specs.push_back(win_spec));
+}
+
 /**
   Set lock for all tables in current select level.
 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 1948d3e98d7..38a03428ee0 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -53,6 +53,7 @@
 #include "log_slow.h"
 #include "sql_derived.h"
 #include "sql_statistics.h"
+#include "sql_window.h"
 
 #include "debug_sync.h"          // DEBUG_SYNC
 #include <m_ctype.h>
@@ -621,6 +622,7 @@ setup_without_group(THD *thd, Ref_ptr_array ref_pointer_array,
                               COND **conds,
                               ORDER *order,
                               ORDER *group,
+                              List<Window_spec> &win_specs,
                               bool *hidden_group_fields,
                               uint *reserved)
 {
@@ -654,6 +656,8 @@ setup_without_group(THD *thd, Ref_ptr_array ref_pointer_array,
   res= res || setup_group(thd, ref_pointer_array, tables, fields, all_fields,
                           group, hidden_group_fields);
   thd->lex->allow_sum_func= save_allow_sum_func;
+  res= res || setup_windows(thd, ref_pointer_array, tables, fields, all_fields,
+                            win_specs);
   DBUG_RETURN(res);
 }
 
@@ -794,6 +798,7 @@ JOIN::prepare(TABLE_LIST *tables_init,
   if (setup_without_group(thd, ref_ptrs, tables_list,
                           select_lex->leaf_tables, fields_list,
                           all_fields, &conds, order, group_list,
+                          select_lex->window_specs,
                           &hidden_group_fields,
                           &select_lex->select_n_reserved))
     DBUG_RETURN(-1);
diff --git a/sql/sql_window.cc b/sql/sql_window.cc
new file mode 100644
index 00000000000..493a9686ff8
--- /dev/null
+++ b/sql/sql_window.cc
@@ -0,0 +1,79 @@
+#include "sql_select.h"
+#include "sql_window.h"
+
+
+bool
+Window_spec::check_window_names(List_iterator_fast<Window_spec> &it)
+{
+  char *name= this->name();
+  char *ref_name= window_reference();
+  bool win_ref_is_resolved= false;
+  it.rewind();
+  Window_spec *win_spec;
+  while((win_spec= it++) && win_spec != this)
+  {
+    char *win_spec_name= win_spec->name();
+    if (win_spec_name)
+    {
+      if (name && my_strcasecmp(system_charset_info, name, win_spec_name) == 0)
+      {
+        my_error(ER_DUP_WINDOW_NAME, MYF(0), name);
+        return true;
+      }
+      if (ref_name &&
+          my_strcasecmp(system_charset_info, ref_name, win_spec_name) == 0)
+      {
+        if (win_spec->partition_list.elements)
+	{
+          my_error(ER_PARTITION_LIST_IN_REFERENCING_WINDOW_SPEC, MYF(0),
+                   ref_name);
+          return true;
+        }
+        if (win_spec->order_list.elements && order_list.elements)
+	{
+          my_error(ER_ORDER_LIST_IN_REFERENCING_WINDOW_SPEC, MYF(0), ref_name);
+          return true;              
+        } 
+        if (win_spec->window_frame) 
+	{
+          my_error(ER_WINDOW_FRAME_IN_REFERENCED_WINDOW_SPEC, MYF(0), ref_name);
+          return true;              
+        }
+        referenced_win_spec=win_spec; 
+        win_ref_is_resolved= true; 
+      }
+    }
+  }
+  if (ref_name && !win_ref_is_resolved)
+  {
+    my_error(ER_WRONG_WINDOW_SPEC_NAME, MYF(0), ref_name);
+    return true;              
+  }
+  return false;
+}
+
+
+int
+setup_windows(THD *thd, Ref_ptr_array ref_pointer_array, TABLE_LIST *tables,
+	      List<Item> &fields, List<Item> &all_fields, 
+              List<Window_spec> win_specs)
+{
+  Window_spec *win_spec;
+  DBUG_ENTER("setup_windows");
+  List_iterator<Window_spec> it(win_specs);
+  List_iterator_fast<Window_spec> itp(win_specs);
+    
+  while ((win_spec= it++))
+  {
+    bool hidden_group_fields;
+    if (win_spec->check_window_names(itp) ||
+        setup_group(thd, ref_pointer_array, tables, fields, all_fields,
+                    win_spec->partition_list.first, &hidden_group_fields) ||
+        setup_order(thd, ref_pointer_array, tables, fields, all_fields,
+                    win_spec->order_list.first))
+    {
+      DBUG_RETURN(1);
+    }
+  }
+  DBUG_RETURN(0);
+}
diff --git a/sql/sql_window.h b/sql/sql_window.h
new file mode 100644
index 00000000000..680dbcfd63f
--- /dev/null
+++ b/sql/sql_window.h
@@ -0,0 +1,124 @@
+
+#ifndef SQL_WINDOW_INCLUDED
+#define SQL_WINDOW_INCLUDED
+
+#include "my_global.h"
+#include "item.h"
+
+class Window_frame_bound : public Sql_alloc
+{
+
+public:
+ 
+  enum Bound_precedence_type
+  {
+    PRECEDING,
+    CURRENT,           // Used for CURRENT ROW window frame bounds
+    FOLLOWING
+  };
+
+  Bound_precedence_type precedence_type;
+ 
+
+  /* 
+    For UNBOUNDED PRECEDING / UNBOUNDED FOLLOWING window frame bounds
+    precedence type is seto to PRECEDING / FOLLOWING and
+    offset is set to NULL. 
+    The offset is not meaningful with precedence type CURRENT 
+  */
+  Item *offset;
+
+  Window_frame_bound(Bound_precedence_type prec_type,
+                     Item *offset_val)
+    : precedence_type(prec_type), offset(offset_val) {}
+ 
+};
+
+
+class Window_frame : public Sql_alloc
+{
+  
+public:
+
+  enum Frame_units
+  {
+    UNITS_ROWS,
+    UNITS_RANGE
+  };
+
+  enum Frame_exclusion
+  {
+    EXCL_NONE,
+    EXCL_CURRENT_ROW,
+    EXCL_GROUP,
+    EXCL_TIES
+  };
+
+  Frame_units units;
+
+  Window_frame_bound *top_bound;
+
+  Window_frame_bound *bottom_bound;
+
+  Frame_exclusion exclusion;
+
+  Window_frame(Frame_units win_frame_units,
+               Window_frame_bound *win_frame_top_bound,
+               Window_frame_bound *win_frame_bottom_bound,
+               Frame_exclusion win_frame_exclusion)
+    : units(win_frame_units), top_bound(win_frame_top_bound),
+      bottom_bound(win_frame_bottom_bound), exclusion(win_frame_exclusion) {}
+
+};
+
+class Window_spec : public Sql_alloc
+{
+ public:
+
+  LEX_STRING *window_ref;
+
+  SQL_I_List<ORDER> partition_list;
+
+  SQL_I_List<ORDER> order_list;
+
+  Window_frame *window_frame;
+
+  Window_spec *referenced_win_spec;
+
+  Window_spec(LEX_STRING *win_ref, 
+              SQL_I_List<ORDER> part_list,
+              SQL_I_List<ORDER> ord_list,
+              Window_frame *win_frame)
+    : window_ref(win_ref), partition_list(part_list), order_list(ord_list),
+    window_frame(win_frame), referenced_win_spec(NULL) {}
+
+    virtual char *name() { return NULL; }
+
+    bool check_window_names(List_iterator_fast<Window_spec> &it);
+
+    char *window_reference() { return window_ref ? window_ref->str : NULL; }
+};
+
+class Window_def : public Window_spec
+{
+ public:
+
+  LEX_STRING *window_name;
+
+  Window_def(LEX_STRING *win_name,
+             LEX_STRING *win_ref, 
+             SQL_I_List<ORDER> part_list,
+             SQL_I_List<ORDER> ord_list,
+             Window_frame *win_frame) 
+    : Window_spec(win_ref, part_list, ord_list, win_frame),
+      window_name(win_name) {}
+ 
+    char *name() { return window_name->str; }
+
+};
+
+int setup_windows(THD *thd, Ref_ptr_array ref_pointer_array, TABLE_LIST *tables,
+	          List<Item> &fields, List<Item> &all_fields, 
+                  List<Window_spec> win_specs);
+
+#endif /* SQL_WINDOW_INCLUDED */
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 3eb6a99a131..3fa73b72e60 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -54,6 +54,8 @@
 #include "sql_handler.h"                       // Sql_cmd_handler_*
 #include "sql_signal.h"
 #include "sql_get_diagnostics.h"               // Sql_cmd_get_diagnostics
+#include "sql_window.h"
+#include "item_windowfunc.h"
 #include "event_parse_data.h"
 #include "create_options.h"
 #include <myisam.h>
@@ -962,6 +964,8 @@ bool LEX::set_bincmp(CHARSET_INFO *cs, bool bin)
   handlerton *db_type;
   st_select_lex *select_lex;
   struct p_elem_val *p_elem_value;
+  class Window_frame *window_frame;
+  class Window_frame_bound *window_frame_bound;
   udf_func *udf;
 
   /* enums */
@@ -987,6 +991,9 @@ bool LEX::set_bincmp(CHARSET_INFO *cs, bool bin)
   enum sp_variable::enum_mode spvar_mode;
   enum thr_lock_type lock_type;
   enum enum_mysql_timestamp_type date_time_type;
+  enum Window_frame_bound::Bound_precedence_type bound_precedence_type;
+  enum Window_frame::Frame_units frame_units;
+  enum Window_frame::Frame_exclusion frame_exclusion;
   DDL_options_st object_ddl_options;
 }
 
@@ -998,10 +1005,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %parse-param { THD *thd }
 %lex-param { THD *thd }
 /*
-  Currently there are 121 shift/reduce conflicts.
+  Currently there are 124 shift/reduce conflicts.
   We should not introduce new conflicts any more.
 */
-%expect 121
+%expect 124
 
 /*
    Comments for TOKENS.
@@ -1124,6 +1131,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  CREATE                        /* SQL-2003-R */
 %token  CROSS                         /* SQL-2003-R */
 %token  CUBE_SYM                      /* SQL-2003-R */
+%token  CUME_DIST_SYM
 %token  CURDATE                       /* MYSQL-FUNC */
 %token  CURRENT_SYM                   /* SQL-2003-R */
 %token  CURRENT_USER                  /* SQL-2003-R */
@@ -1154,6 +1162,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  DELAYED_SYM
 %token  DELAY_KEY_WRITE_SYM
 %token  DELETE_SYM                    /* SQL-2003-R */
+%token  DENSE_RANK_SYM
 %token  DESC                          /* SQL-2003-N */
 %token  DESCRIBE                      /* SQL-2003-R */
 %token  DES_KEY_FILE
@@ -1195,6 +1204,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  EVERY_SYM                     /* SQL-2003-N */
 %token  EXCHANGE_SYM
 %token  EXAMINED_SYM
+%token  EXCLUDE_SYM
 %token  EXECUTE_SYM                   /* SQL-2003-R */
 %token  EXISTS                        /* SQL-2003-R */
 %token  EXIT_SYM
@@ -1213,6 +1223,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  FLOAT_NUM
 %token  FLOAT_SYM                     /* SQL-2003-R */
 %token  FLUSH_SYM
+%token  FOLLOWING_SYM
 %token  FORCE_SYM
 %token  FOREIGN                       /* SQL-2003-R */
 %token  FOR_SYM                       /* SQL-2003-R */
@@ -1409,9 +1420,11 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  ORDER_SYM                     /* SQL-2003-R */
 %token  OR_OR_SYM                     /* OPERATOR */
 %token  OR_SYM                        /* SQL-2003-R */
+%token  OTHERS_SYM            
 %token  OUTER
 %token  OUTFILE
 %token  OUT_SYM                       /* SQL-2003-R */
+%token  OVER_SYM
 %token  OWNER_SYM
 %token  PACK_KEYS_SYM
 %token  PAGE_SYM
@@ -1424,6 +1437,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  PARTITIONS_SYM
 %token  PARTITIONING_SYM
 %token  PASSWORD_SYM
+%token  PERCENT_RANK_SYM
 %token  PERSISTENT_SYM
 %token  PHASE_SYM
 %token  PLUGINS_SYM
@@ -1432,6 +1446,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  POLYGON
 %token  PORT_SYM
 %token  POSITION_SYM                  /* SQL-2003-N */
+%token  PRECEDING_SYM
 %token  PRECISION                     /* SQL-2003-R */
 %token  PREPARE_SYM                   /* SQL-2003-R */
 %token  PRESERVE_SYM
@@ -1449,6 +1464,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  QUERY_SYM
 %token  QUICK
 %token  RANGE_SYM                     /* SQL-2003-R */
+%token  RANK_SYM        
 %token  READS_SYM                     /* SQL-2003-R */
 %token  READ_ONLY_SYM
 %token  READ_SYM                      /* SQL-2003-N */
@@ -1498,6 +1514,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  ROW_FORMAT_SYM
 %token  ROW_SYM                       /* SQL-2003-R */
 %token  ROW_COUNT_SYM                 /* SQL-2003-N */
+%token  ROW_NUMBER_SYM
 %token  RTREE_SYM
 %token  SAVEPOINT_SYM                 /* SQL-2003-R */
 %token  SCHEDULE_SYM
@@ -1588,6 +1605,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  TEXT_SYM
 %token  THAN_SYM
 %token  THEN_SYM                      /* SQL-2003-R */
+%token  TIES_SYM
 %token  TIMESTAMP                     /* SQL-2003-R */
 %token  TIMESTAMP_ADD
 %token  TIMESTAMP_DIFF
@@ -1608,6 +1626,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  TYPE_SYM                      /* SQL-2003-N */
 %token  UDF_RETURNS_SYM
 %token  ULONGLONG_NUM
+%token  UNBOUNDED_SYM
 %token  UNCOMMITTED_SYM               /* SQL-2003-N */
 %token  UNDEFINED_SYM
 %token  UNDERSCORE_CHARSET
@@ -1649,6 +1668,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  WEIGHT_STRING_SYM
 %token  WHEN_SYM                      /* SQL-2003-R */
 %token  WHERE                         /* SQL-2003-R */
+%token  WINDOW_SYM
 %token  WHILE_SYM
 %token  WITH                          /* SQL-2003-R */
 %token  WITH_CUBE_SYM                 /* INTERNAL */
@@ -1787,6 +1807,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
         simple_ident_nospvar simple_ident_q
         field_or_var limit_option
         part_func_expr
+        window_func_expr
+        window_func
+        simple_window_func
         function_call_keyword
         function_call_nonkeyword
         function_call_generic
@@ -1975,6 +1998,15 @@ END_OF_INPUT
 %type <cond_info_item_name> condition_information_item_name;
 %type <cond_info_list> condition_information;
 
+%type <NONE> opt_window_clause window_def_list window_def window_spec
+%type <lex_str_ptr> window_name
+%type <NONE> opt_window_ref opt_window_frame_clause
+%type <frame_units> window_frame_units;
+%type <NONE> window_frame_extent;
+%type <frame_exclusion> opt_window_frame_exclusion;
+%type <window_frame_bound> window_frame_start window_frame_bound;
+
+
 %type <NONE>
         '-' '+' '*' '/' '%' '(' ')'
         ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM OR_OR_SYM BETWEEN_SYM CASE_SYM
@@ -8497,6 +8529,7 @@ table_expression:
           opt_where_clause
           opt_group_clause
           opt_having_clause
+          opt_window_clause
           opt_order_clause
           opt_limit_clause
           opt_procedure_clause
@@ -9221,6 +9254,7 @@ simple_expr:
         | param_marker { $$= $1; }
         | variable
         | sum_expr
+        | window_func_expr
         | simple_expr OR_OR_SYM simple_expr
           {
             $$= new (thd->mem_root) Item_func_concat(thd, $1, $3);
@@ -10356,6 +10390,81 @@ sum_expr:
           }
         ;
 
+window_func_expr:
+          window_func OVER_SYM window_name
+          {
+            $$= new (thd->mem_root) Item_window_func(thd, (Item_sum *) $1, $3);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        |
+          window_func OVER_SYM window_spec
+          {
+            LEX *lex= Lex;
+            if (Select->add_window_spec(thd, lex->win_ref,
+                                        Select->group_list,
+                                        Select->order_list,
+                                        lex->win_frame))
+              MYSQL_YYABORT;
+            $$= new (thd->mem_root) Item_window_func(thd, (Item_sum *) $1,
+                                                      thd->lex->win_spec); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
+window_func:
+          simple_window_func
+        |
+          sum_expr
+        ;
+
+simple_window_func:
+          ROW_NUMBER_SYM '(' ')'
+          {
+            $$= new (thd->mem_root) Item_sum_row_number(thd);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        |
+          RANK_SYM '(' ')'
+          {
+            $$= new (thd->mem_root) Item_sum_rank(thd);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        |
+          DENSE_RANK_SYM '(' ')'
+          {
+            $$= new (thd->mem_root) Item_sum_dense_rank(thd);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        |
+          PERCENT_RANK_SYM '(' ')'
+          {
+            $$= new (thd->mem_root) Item_sum_percent_rank(thd);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        |
+          CUME_DIST_SYM '(' ')'
+          {
+            $$= new (thd->mem_root) Item_sum_cume_dist(thd);
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
+window_name:
+          ident
+          {
+            $$= (LEX_STRING *) thd->memdup(&$1, sizeof(LEX_STRING));
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
 variable:
           '@'
           {
@@ -11290,6 +11399,155 @@ olap_opt:
         ;
 
 /*
+  optional window clause in select
+*/
+
+opt_window_clause:
+          /* empty */
+          {}
+        | WINDOW_SYM
+          window_def_list
+          {}
+        ;
+
+window_def_list:
+          window_def_list ',' window_def
+        | window_def
+        ;
+
+window_def:
+          window_name AS window_spec
+          { 
+            LEX *lex= Lex;
+            if (Select->add_window_def(thd, $1, lex->win_ref,
+                                       Select->group_list,
+                                       Select->order_list,
+                                       lex->win_frame ))
+              MYSQL_YYABORT;
+          }
+        ;
+
+window_spec:
+          '(' 
+          { Select->prepare_add_window_spec(thd); }
+          opt_window_ref opt_window_partition_clause
+          opt_window_order_clause opt_window_frame_clause
+          ')'
+        ;
+
+opt_window_ref:
+          /* empty */ {} 
+        | ident
+          {
+            thd->lex->win_ref= (LEX_STRING *) thd->memdup(&$1, sizeof(LEX_STRING));
+            if (thd->lex->win_ref == NULL)
+              MYSQL_YYABORT;
+          }
+
+opt_window_partition_clause:
+          /* empty */ { }
+        | PARTITION_SYM BY group_list
+        ;
+
+opt_window_order_clause:
+          /* empty */ { }
+        | ORDER_SYM BY order_list
+        ;
+
+opt_window_frame_clause:
+          /* empty */ {}
+        | window_frame_units window_frame_extent opt_window_frame_exclusion
+          {
+            LEX *lex= Lex;
+            lex->win_frame=
+              new (thd->mem_root) Window_frame($1,
+                                               lex->frame_top_bound,
+                                               lex->frame_bottom_bound,
+                                               $3);
+            if (lex->win_frame == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
+window_frame_units:
+          ROWS_SYM { $$= Window_frame::UNITS_ROWS; }
+        | RANGE_SYM { $$= Window_frame::UNITS_RANGE; }
+        ;
+         
+window_frame_extent:
+          window_frame_start
+          {
+            LEX *lex= Lex;
+            lex->frame_top_bound= $1;
+            lex->frame_bottom_bound=
+              new (thd->mem_root)
+                Window_frame_bound(Window_frame_bound::CURRENT, NULL);
+            if (lex->frame_bottom_bound == NULL)
+              MYSQL_YYABORT;
+          }
+        | BETWEEN_SYM window_frame_bound AND_SYM window_frame_bound
+          {
+            LEX *lex= Lex;
+            lex->frame_top_bound= $2;
+            lex->frame_bottom_bound= $4;
+          }
+        ;
+
+window_frame_start:
+          UNBOUNDED_SYM PRECEDING_SYM
+          {
+            $$= new (thd->mem_root) 
+                  Window_frame_bound(Window_frame_bound::PRECEDING, NULL); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          } 
+        | CURRENT_SYM ROW_SYM
+          { 
+            $$= new (thd->mem_root)
+                  Window_frame_bound(Window_frame_bound::CURRENT, NULL); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        | literal PRECEDING_SYM
+          {
+            $$= new (thd->mem_root)
+                  Window_frame_bound(Window_frame_bound::PRECEDING, $1); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
+window_frame_bound:
+          window_frame_start { $$= $1; }
+        | UNBOUNDED_SYM FOLLOWING_SYM        
+          {
+            $$= new (thd->mem_root)
+                  Window_frame_bound(Window_frame_bound::FOLLOWING, NULL); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          } 
+        | literal FOLLOWING_SYM
+          {
+            $$= new (thd->mem_root)
+                  Window_frame_bound(Window_frame_bound::FOLLOWING, $1); 
+            if ($$ == NULL)
+              MYSQL_YYABORT;
+          }
+        ;
+
+opt_window_frame_exclusion:
+          /* empty */ { $$= Window_frame::EXCL_NONE; }
+        | EXCLUDE_SYM CURRENT_SYM ROW_SYM
+          { $$= Window_frame::EXCL_CURRENT_ROW; }
+        | EXCLUDE_SYM GROUP_SYM
+          { $$= Window_frame::EXCL_GROUP; }
+        | EXCLUDE_SYM TIES_SYM
+          { $$= Window_frame::EXCL_TIES; }
+        | EXCLUDE_SYM NO_SYM OTHERS_SYM
+          { $$= Window_frame::EXCL_NONE; }
+        ;      
+       
+/*
   Order by statement in ALTER TABLE
 */