Fix for add_group_number with Equal_Count

distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Base_Generator.enso

@@ -645,10 +645,16 @@ make_group_number_equal_count (arguments : Vector) = if arguments.length < 3 the
 
     ordering_part = if ordering.length == 0 then "" else
         SQL_Builder.code "ORDER BY " ++ SQL_Builder.join ", " ordering
+    count = SQL_Builder.code "(count(*) over ())"
     row_number_minus_1 = SQL_Builder.code "((row_number() over (" ++ ordering_part ++ ")) - 1)"
-    group_size = SQL_Builder.code "(((count(*) over ()) + (" ++ group_count.paren ++ " - 1)) / " ++ group_count.paren ++ ")"
-    base_value = SQL_Builder.code "(" ++ row_number_minus_1 ++ " / " ++ group_size ++ " + 1)"
-    SQL_Builder.code "((" ++ base_value.paren ++ " * " ++ step.paren ++ ") + " ++ offset.paren ++ ")"
+    small_group_size = SQL_Builder.code "(" ++ count ++ " / " ++ group_count.paren ++ ")"
+    extra = SQL_Builder.code "(" ++ count ++ " % " ++ group_count.paren ++ ")"
+    is_in_large_groups = SQL_Builder.code "(" ++ row_number_minus_1 ++ " < (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1)))"
+    gn_large_groups = SQL_Builder.code "(" ++ row_number_minus_1 ++ " / (" ++ small_group_size.paren ++ " + 1))"
+    gn_small_groups = SQL_Builder.code "(((" ++ row_number_minus_1 ++ " - (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1))) / " ++ small_group_size.paren ++ ") + " ++ extra.paren ++ ")"
+    base_group_number = SQL_Builder.code "(case when " ++ is_in_large_groups.paren ++ " then " ++ gn_large_groups.paren ++ " else " ++ gn_small_groups.paren ++ " end)"
+
+    SQL_Builder.code "((" ++ base_group_number.paren ++ " * " ++ step.paren ++ ") + " ++ offset.paren ++ ")"
 
 ## ---
    private: true

distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Common/Group_Number_Helpers.enso

@@ -15,7 +15,5 @@ make_group_number (from : Integer) (step : Integer) (grouping_expressions : Vect
    private: true
    ---
 make_group_number_equal_count (from : Integer) (step : Integer) (group_count : Integer) (ordering_expressions : Vector SQL_IR_Expression) -> SQL_IR_Expression =
-    # The SQL row_number() counts from 1, so we adjust the offset.
-    offset = (from - step) : Integer
-    params = [SQL_IR_Expression.Literal offset.to_text, SQL_IR_Expression.Literal step.to_text, SQL_IR_Expression.Literal group_count.to_text] + ordering_expressions
+    params = [SQL_IR_Expression.Literal from.to_text, SQL_IR_Expression.Literal step.to_text, SQL_IR_Expression.Literal group_count.to_text] + ordering_expressions
     SQL_IR_Expression.Operation "GROUP_NUMBER_EQUAL_COUNT" params

distribution/lib/Standard/DuckDB/0.0.0-dev/src/Internal/DuckDB_Dialect.enso

@@ -506,22 +506,26 @@ make_date_diff arguments (metadata : Date_Period_Metadata) =
 ## ---
    private: true
    ---
-   GroupNumber = FLOOR(RowNumber / CEIL(TotalRowCount / GroupCount)) (0 based)
 make_group_number_equal_count : Vector SQL_Builder -> SQL_Builder
 make_group_number_equal_count (arguments : Vector) = if arguments.length < 3 then Error.throw (Illegal_State.Error "Wrong amount of parameters in GROUP_NUMBER_EQUAL_COUNT IR. This is a bug in the Database library.") else
-    ordering = arguments.drop 3
-    ordering_part = if ordering.length == 0 then "" else
-        SQL_Builder.code " OVER (ORDER BY " ++ SQL_Builder.join ", " ordering ++ ")"
-    row_number_minus_1 = (SQL_Builder.code "ROW_NUMBER()" ++ ordering_part).paren ++ " - 1"
-
+    offset = arguments.at 0
+    step = arguments.at 1
     group_count = arguments.at 2
-    group_size = SQL_Builder.code "CEIL((COUNT(*) OVER ()) / " ++ group_count ++ ")"
 
-    base_value = SQL_Builder.code "FLOOR(" ++ row_number_minus_1.paren ++ " / " ++ group_size ++ ") + 1"
+    ordering = arguments.drop 3
 
-    offset = arguments.at 0
-    step = arguments.at 1
-    (base_value.paren ++ " * " ++ step) . paren ++ " + " ++ offset
+    ordering_part = if ordering.length == 0 then "" else
+        SQL_Builder.code "ORDER BY " ++ SQL_Builder.join ", " ordering
+    count = SQL_Builder.code "(count(*) over ())"
+    row_number_minus_1 = SQL_Builder.code "((row_number() over (" ++ ordering_part ++ ")) - 1)"
+    small_group_size = SQL_Builder.code "(floor(" ++ count ++ " / " ++ group_count.paren ++ "))"
+    extra = SQL_Builder.code "(" ++ count ++ " % " ++ group_count.paren ++ ")"
+    is_in_large_groups = SQL_Builder.code "(" ++ row_number_minus_1 ++ " < (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1)))"
+    gn_large_groups = SQL_Builder.code "(floor(" ++ row_number_minus_1 ++ " / (" ++ small_group_size.paren ++ " + 1)))"
+    gn_small_groups = SQL_Builder.code "(floor(((" ++ row_number_minus_1 ++ " - (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1))) / " ++ small_group_size.paren ++ ") + " ++ extra.paren ++ "))"
+    base_group_number = SQL_Builder.code "(case when " ++ is_in_large_groups.paren ++ " then " ++ gn_large_groups.paren ++ " else " ++ gn_small_groups.paren ++ " end)"
+
+    SQL_Builder.code "((" ++ base_group_number.paren ++ " * " ++ step.paren ++ ") + " ++ offset.paren ++ ")"
 
 ## ---
    private: true

distribution/lib/Standard/Snowflake/0.0.0-dev/src/Internal/Snowflake_Dialect.enso

@@ -650,12 +650,16 @@ make_group_number_equal_count (arguments : Vector) = if arguments.length < 3 the
 
     ordering_part = if ordering.length == 0 then "" else
         SQL_Builder.code "ORDER BY " ++ SQL_Builder.join ", " ordering
+    count = SQL_Builder.code "(count(*) over ())"
     row_number_minus_1 = SQL_Builder.code "((row_number() over (" ++ ordering_part ++ ")) - 1)"
-    group_size_f = SQL_Builder.code "(((count(*) over ()) + (" ++ group_count.paren ++ " - 1)) / " ++ group_count.paren ++ ")"
-    group_size = SQL_Builder.code "FLOOR(" ++ group_size_f.paren ++ ")"
-    base_value_f = SQL_Builder.code "(" ++ row_number_minus_1 ++ " / " ++ group_size ++ " + 1)"
-    base_value = SQL_Builder.code "FLOOR(" ++ base_value_f.paren ++ ")"
-    SQL_Builder.code "((" ++ base_value.paren ++ " * " ++ step.paren ++ ") + " ++ offset.paren ++ ")"
+    small_group_size = SQL_Builder.code "(floor(" ++ count ++ " / " ++ group_count.paren ++ "))"
+    extra = SQL_Builder.code "(" ++ count ++ " % " ++ group_count.paren ++ ")"
+    is_in_large_groups = SQL_Builder.code "(" ++ row_number_minus_1 ++ " < (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1)))"
+    gn_large_groups = SQL_Builder.code "(floor(" ++ row_number_minus_1 ++ " / (" ++ small_group_size.paren ++ " + 1)))"
+    gn_small_groups = SQL_Builder.code "(floor(((" ++ row_number_minus_1 ++ " - (" ++ extra.paren ++ " * (" ++ small_group_size.paren ++ " + 1))) / " ++ small_group_size.paren ++ ") + " ++ extra.paren ++ "))"
+    base_group_number = SQL_Builder.code "(case when " ++ is_in_large_groups.paren ++ " then " ++ gn_large_groups.paren ++ " else " ++ gn_small_groups.paren ++ " end)"
+
+    SQL_Builder.code "((" ++ base_group_number.paren ++ " * " ++ step.paren ++ ") + " ++ offset.paren ++ ")"
 
 ## ---
    private: true

distribution/lib/Standard/Table/0.0.0-dev/src/Internal/Unique_Name_Strategy.enso

@@ -141,7 +141,8 @@ type Unique_Name_Strategy
        private: true
        advanced: true
        ---
-       Takes a name and gets a unique version.
+       Takes a name and gets a unique version. Marks the newly created name as
+       used.
 
        ## Arguments
         - `name`: The column name to make unique.

test/Table_Tests/src/Common_Table_Operations/Add_Group_Number_Spec.enso

@@ -65,15 +65,20 @@ add_group_number_specs suite_builder setup =
             g3 = t.add_group_number (..Equal_Count 5) "g"
             g3.at 'g' . to_vector . should_equal [0, 0, 1, 1, 2, 2, 3, 3, 4]
 
+            big_t = table_builder [['x', (0.up_to (298*5 + 1)).to_vector]] . order_by ['x']
+            big_t_grouped = big_t.add_group_number (..Equal_Count 5) "g"
+            big_t_counted = big_t_grouped . aggregate "g" [Aggregate_Column.Count] . order_by "g"
+            big_t_counted.at 'Count' . to_vector . should_equal [299, 298, 298, 298, 298]
+
         group_builder.specify "should add group number by equal counts, with order_by" <|
             t = table_builder [['x', [1, 2, 3, 4, 5, 6, 7, 8, 9]], ['y', [9, 8, 7, 6, 5, 4, 3, 2, 1]]] . order_by ['x']
 
             g0 = t.add_group_number (..Equal_Count 4 ['x']) "g" . sort ['x']
-            g0.at 'g' . to_vector . should_equal [0, 0, 0, 1, 1, 1, 2, 2, 2]
+            g0.at 'g' . to_vector . should_equal [0, 0, 0, 1, 1, 2, 2, 3, 3]
             g0.at 'x' . to_vector . should_equal [1, 2, 3, 4, 5, 6, 7, 8, 9]
 
             g1 = t.add_group_number (..Equal_Count 4 ['y']) "g" . sort ['y']
-            g1.at 'g' . to_vector . should_equal [0, 0, 0, 1, 1, 1, 2, 2, 2]
+            g1.at 'g' . to_vector . should_equal [0, 0, 0, 1, 1, 2, 2, 3, 3]
             g1.at 'x' . to_vector . should_equal [9, 8, 7, 6, 5, 4, 3, 2, 1]
 
         group_builder.specify "should add group number by unique values, with from and step" <|