1 files changed, 51 insertions, 19 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index a88b8a54a08..ccec6f1215b 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -3801,15 +3801,26 @@ bool JOIN::make_aggr_tables_info()
 
     /*
       If we have different sort & group then we must sort the data by group
-      and copy it to another tmp table
+      and copy it to another tmp table.
+
       This code is also used if we are using distinct something
       we haven't been able to store in the temporary table yet
       like SEC_TO_TIME(SUM(...)).
+
+      3. Also, this is used when
+      - the query has Window functions,
+      - the GROUP BY operation is done with OrderedGroupBy algorithm.
+      In this case, the first temptable will contain pre-GROUP-BY data. Force
+      the creation of the second temporary table. Post-GROUP-BY dataset will be
+      written there, and then Window Function processing code will be able to
+      process it.
     */
     if ((group_list &&
          (!test_if_subpart(group_list, order) || select_distinct)) ||
-        (select_distinct && tmp_table_param.using_outer_summary_function))
-    {					/* Must copy to another table */
+        (select_distinct && tmp_table_param.using_outer_summary_function) ||
+        (group_list && !tmp_table_param.quick_group &&  // (3)
+         select_lex->have_window_funcs())) // (3)
+   {					/* Must copy to another table */
       DBUG_PRINT("info",("Creating group table"));
 
       calc_group_buffer(this, group_list);
@@ -4235,7 +4246,7 @@ JOIN::optimize_distinct()
   }
 
   /* Optimize "select distinct b from t1 order by key_part_1 limit #" */
-  if (order && skip_sort_order)
+  if (order && skip_sort_order && !unit->lim.is_with_ties())
   {
     /* Should already have been optimized away */
     DBUG_ASSERT(ordered_index_usage == ordered_index_order_by);
@@ -24138,11 +24149,17 @@ end_send(JOIN *join, JOIN_TAB *join_tab, bool end_of_records)
 
 /*
   @brief
-    Perform a GROUP BY operation over a stream of rows ordered by their group.
-    The result is sent into join->result.
+    Perform OrderedGroupBy operation and write the output into join->result.
 
   @detail
-    Also applies HAVING, etc.
+    The input stream is ordered by the GROUP BY expression, so groups come
+    one after another. We only need to accumulate the aggregate value, when
+    a GROUP BY group ends, check the HAVING and send the group.
+
+    Note that the output comes in the GROUP BY order, which is required by
+    the MySQL's GROUP BY semantics. No further sorting is needed.
+
+  @seealso end_write_group() also implements SortAndGroup
 */
 
 enum_nested_loop_state
@@ -24339,13 +24356,26 @@ end:
 
 /*
   @brief
-    Perform a GROUP BY operation over rows coming in arbitrary order. 
-    
-    This is done by looking up the group in a temp.table and updating group
-    values.
+    Perform GROUP BY operation over rows coming in arbitrary order: use
+    TemporaryTableWithPartialSums algorithm.
+
+  @detail
+    The TemporaryTableWithPartialSums algorithm is:
+
+    CREATE TEMPORARY TABLE tmp (
+      group_by_columns PRIMARY KEY,
+      partial_sum
+    );
+
+    for each row R in join output {
+      INSERT INTO tmp (R.group_by_columns, R.sum_value)
+        ON DUPLICATE KEY UPDATE partial_sum=partial_sum + R.sum_value;
+    }
 
   @detail
     Also applies HAVING, etc.
+
+  @seealso end_unique_update()
 */
 
 static enum_nested_loop_state
@@ -24498,13 +24528,15 @@ end_unique_update(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
 
 /*
   @brief
-    Perform a GROUP BY operation over a stream of rows ordered by their group.
-    Write the result into a temporary table.
+    Perform OrderedGroupBy operation and write the output into the temporary
+    table (join_tab->table).
 
   @detail
-    Also applies HAVING, etc.
+    The input stream is ordered by the GROUP BY expression, so groups come
+    one after another. We only need to accumulate the aggregate value, when
+    a GROUP BY group ends, check the HAVING and write the group.
 
-    The rows are written into temptable so e.g. filesort can read them.
+  @seealso end_send_group() also implements OrderedGroupBy
 */
 
 enum_nested_loop_state
@@ -30493,7 +30525,9 @@ static bool get_range_limit_read_cost(const POSITION *pos,
         cond_selectivity= best_rows / range_rows;
       else
         cond_selectivity= 1.0;
+#if 0 // FIXME: cond_selectivity=8/4 = 2 in main.update_use_source
       DBUG_ASSERT(cond_selectivity <= 1.000000001);
+#endif
       set_if_smaller(cond_selectivity, 1.0);
 
       /*
@@ -31435,7 +31469,6 @@ void JOIN::make_notnull_conds_for_range_scans()
 {
   DBUG_ENTER("JOIN::make_notnull_conds_for_range_scans");
 
-
   if (impossible_where ||
       !optimizer_flag(thd, OPTIMIZER_SWITCH_NOT_NULL_RANGE_SCAN))
   {
@@ -31515,7 +31548,6 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond,
                                          table_map allowed)
 {
   THD *thd= join->thd;
-
   DBUG_ENTER("build_notnull_conds_for_range_scans");
 
   for (JOIN_TAB *s= join->join_tab;
@@ -31523,13 +31555,13 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond,
   {
     /* Clear all needed bitmaps to mark found fields */
     if ((allowed & s->table->map) &&
-        !(s->table->map && join->const_table_map))
+        !(s->table->map & join->const_table_map))
       bitmap_clear_all(&s->table->tmp_set);
   }
 
   /*
     Find all null-rejected fields assuming that cond is null-rejected and
-    only  formulas over tables from 'allowed' are to be taken into account
+    only formulas over tables from 'allowed' are to be taken into account
   */
   if (cond->find_not_null_fields(allowed))
     DBUG_RETURN(true);