Merge branch 'cume_dist' into bb-10.2-mdev9543

Author: cvicentiu

mysql-test/r/win_percent_cume.result

@@ -0,0 +1,62 @@
+create table t1 (
+pk int primary key,
+a int,
+b int
+);
+insert into t1 values
+( 1 , 0, 10),
+( 2 , 0, 10),
+( 3 , 1, 10),
+( 4 , 1, 10),
+( 8 , 2, 10),
+( 5 , 2, 20),
+( 6 , 2, 20),
+( 7 , 2, 20),
+( 9 , 4, 20),
+(10 , 4, 20);
+select pk, a, b,
+percent_rank() over (order by a),
+cume_dist() over (order by a)
+from t1;
+pk	a	b	percent_rank() over (order by a)	cume_dist() over (order by a)
+1	0	10	0.0000000000	0.2000000000
+2	0	10	0.0000000000	0.2000000000
+3	1	10	0.2222222222	0.4000000000
+4	1	10	0.2222222222	0.4000000000
+8	2	10	0.4444444444	0.8000000000
+5	2	20	0.4444444444	0.8000000000
+6	2	20	0.4444444444	0.8000000000
+7	2	20	0.4444444444	0.8000000000
+9	4	20	0.8888888889	1.0000000000
+10	4	20	0.8888888889	1.0000000000
+select pk, a, b,
+percent_rank() over (order by pk),
+cume_dist() over (order by pk)
+from t1 order by pk;
+pk	a	b	percent_rank() over (order by pk)	cume_dist() over (order by pk)
+1	0	10	0.0000000000	0.1000000000
+2	0	10	0.1111111111	0.2000000000
+3	1	10	0.2222222222	0.3000000000
+4	1	10	0.3333333333	0.4000000000
+5	2	20	0.4444444444	0.5000000000
+6	2	20	0.5555555556	0.6000000000
+7	2	20	0.6666666667	0.7000000000
+8	2	10	0.7777777778	0.8000000000
+9	4	20	0.8888888889	0.9000000000
+10	4	20	1.0000000000	1.0000000000
+select pk, a, b,
+percent_rank() over (partition by a order by a),
+cume_dist() over (partition by a order by a)
+from t1;
+pk	a	b	percent_rank() over (partition by a order by a)	cume_dist() over (partition by a order by a)
+1	0	10	0.0000000000	1.0000000000
+2	0	10	0.0000000000	1.0000000000
+3	1	10	0.0000000000	1.0000000000
+4	1	10	0.0000000000	1.0000000000
+8	2	10	0.0000000000	1.0000000000
+5	2	20	0.0000000000	1.0000000000
+6	2	20	0.0000000000	1.0000000000
+7	2	20	0.0000000000	1.0000000000
+9	4	20	0.0000000000	1.0000000000
+10	4	20	0.0000000000	1.0000000000
+drop table t1;

mysql-test/t/win_percent_cume.test

@@ -0,0 +1,36 @@
+create table t1 (
+  pk int primary key,
+  a int,
+  b int
+);
+
+
+insert into t1 values
+( 1 , 0, 10),
+( 2 , 0, 10),
+( 3 , 1, 10),
+( 4 , 1, 10),
+( 8 , 2, 10),
+( 5 , 2, 20),
+( 6 , 2, 20),
+( 7 , 2, 20),
+( 9 , 4, 20),
+(10 , 4, 20);
+
+select pk, a, b,
+    percent_rank() over (order by a),
+    cume_dist() over (order by a)
+from t1;
+
+select pk, a, b,
+       percent_rank() over (order by pk),
+       cume_dist() over (order by pk)
+from t1 order by pk;
+
+select pk, a, b,
+        percent_rank() over (partition by a order by a),
+        cume_dist() over (partition by a order by a)
+from t1;
+
+drop table t1;
+

sql/item_windowfunc.h

@@ -317,12 +317,18 @@ class Item_context
   NOTE: All two pass window functions need to implement
   this interface.
 */
-class Item_sum_window_with_context : public Item_sum_num,
-                                     public Item_context
+class Item_sum_window_with_row_count : public Item_sum_num
 {
  public:
-  Item_sum_window_with_context(THD *thd)
-   : Item_sum_num(thd), Item_context() {}
+  Item_sum_window_with_row_count(THD *thd) : Item_sum_num(thd),
+                                             partition_row_count_(0){}
+
+  void set_row_count(ulonglong count) { partition_row_count_ = count; }
+
+ protected:
+  longlong get_row_count() { return partition_row_count_; }
+ private:
+  ulonglong partition_row_count_;
 };
 
 /*
@@ -336,12 +342,11 @@ class Item_sum_window_with_context : public Item_sum_num,
     This is held within the row_count context.
   - Second pass to compute rank of current row and the value of the function
 */
-class Item_sum_percent_rank: public Item_sum_window_with_context,
-                             public Window_context_row_count
+class Item_sum_percent_rank: public Item_sum_window_with_row_count
 {
  public:
   Item_sum_percent_rank(THD *thd)
-    : Item_sum_window_with_context(thd), cur_rank(1) {}
+    : Item_sum_window_with_row_count(thd), cur_rank(1) {}
 
   longlong val_int()
   {
@@ -359,14 +364,9 @@ class Item_sum_percent_rank: public Item_sum_window_with_context,
      We can not get the real value without knowing the number of rows
      in the partition. Don't divide by 0.
    */
-   if (!get_context_())
-   {
-     // Calling this kind of function with a context makes no sense.
-     DBUG_ASSERT(0);
-     return 0;
-   }
-
-   longlong partition_rows = get_context_()->get_field_context(result_field);
+   ulonglong partition_rows = get_row_count();
+   null_value= partition_rows > 0 ? false : true;
+
    return partition_rows > 1 ?
              static_cast<double>(cur_rank - 1) / (partition_rows - 1) : 0;
   }
@@ -381,25 +381,6 @@ class Item_sum_percent_rank: public Item_sum_window_with_context,
     return "percent_rank";
   }
 
-  bool create_window_context()
-  {
-    // TODO-cvicentiu: Currently this means we must make sure to delete
-    // the window context. We can potentially allocate this on the THD memroot.
-    // At the same time, this is only necessary for a small portion of the
-    // query execution and it does not make sense to keep it for all of it.
-    context_ = new Window_context_row_count();
-    if (context_ == NULL)
-      return true;
-    return false;
-  }
-
-  void delete_window_context()
-  {
-    if (context_)
-      delete get_context_();
-    context_ = NULL;
-  }
-
   void update_field() {}
 
   void clear()
@@ -428,13 +409,6 @@ class Item_sum_percent_rank: public Item_sum_window_with_context,
   void cleanup()
   {
     peer_tracker.cleanup();
-    Item_sum_window_with_context::cleanup();
-  }
-
-  /* Helper function so that we don't cast the context every time. */
-  Window_context_row_count* get_context_()
-  {
-    return static_cast<Window_context_row_count *>(context_);
   }
 };
 
@@ -448,27 +422,62 @@ class Item_sum_percent_rank: public Item_sum_window_with_context,
     window ordering of the window partition of R
   - NR is defined to be the number of rows in the window partition of R.
 
-  Just like with Item_sum_percent_rank, compuation of this function requires
+  Just like with Item_sum_percent_rank, computation of this function requires
   two passes.
 */
 
-class Item_sum_cume_dist: public Item_sum_percent_rank
+class Item_sum_cume_dist: public Item_sum_window_with_row_count
 {
  public:
-  Item_sum_cume_dist(THD *thd)
-    : Item_sum_percent_rank(thd) {}
+  Item_sum_cume_dist(THD *thd) : Item_sum_window_with_row_count(thd),
+                                 current_row_count_(0) {}
+
+  double val_real()
+  {
+    if (get_row_count() == 0)
+    {
+      null_value= true;
+      return 0;
+    }
+    ulonglong partition_row_count= get_row_count();
+    null_value= false;
+    return static_cast<double>(current_row_count_) / partition_row_count;
+  }
 
-  double val_real() { return 0; }
+  bool add()
+  {
+    current_row_count_++;
+    return false;
+  }
 
   enum Sumfunctype sum_func () const
   {
     return CUME_DIST_FUNC;
   }
 
+  void clear()
+  {
+    current_row_count_= 0;
+    set_row_count(0);
+  }
+
   const char*func_name() const
   {
     return "cume_dist";
   }
+
+  void update_field() {}
+  enum Item_result result_type () const { return REAL_RESULT; }
+  enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+
+  void fix_length_and_dec()
+  {
+    decimals = 10;  // TODO-cvicentiu find out how many decimals the standard
+                    // requires.
+  }
+
+ private:
+  ulonglong current_row_count_;
 };
 
 
@@ -499,11 +508,11 @@ class Item_window_func : public Item_func_or_sum
       force_return_blank(true),
       read_value_from_result_field(false) {}
 
-  Item_sum *window_func() { return (Item_sum *) args[0]; }
+  Item_sum *window_func() const { return (Item_sum *) args[0]; }
 
   void update_used_tables();
 
-  bool is_frame_prohibited()
+  bool is_frame_prohibited() const
   {
     switch (window_func()->sum_func()) {
     case Item_sum::ROW_NUMBER_FUNC:
@@ -517,7 +526,28 @@ class Item_window_func : public Item_func_or_sum
     }
   }
 
-  bool is_order_list_mandatory()
+  bool requires_partition_size() const
+  {
+    switch (window_func()->sum_func()) {
+    case Item_sum::PERCENT_RANK_FUNC:
+    case Item_sum::CUME_DIST_FUNC:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  bool requires_peer_size() const
+  {
+    switch (window_func()->sum_func()) {
+    case Item_sum::CUME_DIST_FUNC:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  bool is_order_list_mandatory() const
   {
     switch (window_func()->sum_func()) {
     case Item_sum::RANK_FUNC: