Merge pull request #14223 from nikitamikhaylov/update-permutaiton-bug-fix

Fixed incorrect sorting order if LowCardinality column.

src/Columns/ColumnLowCardinality.cpp

@@ -352,7 +352,7 @@ void ColumnLowCardinality::updatePermutation(bool reverse, size_t limit, int nan
         auto new_first = first;
         for (auto j = first + 1; j < last; ++j)
         {
-            if (compareAt(new_first, j, *this, nan_direction_hint) != 0)
+            if (compareAt(res[new_first], res[j], *this, nan_direction_hint) != 0)
             {
                 if (j - new_first > 1)
                     new_ranges.emplace_back(new_first, j);
@@ -376,7 +376,7 @@ void ColumnLowCardinality::updatePermutation(bool reverse, size_t limit, int nan
         auto new_first = first;
         for (auto j = first + 1; j < limit; ++j)
         {
-            if (getDictionary().compareAt(getIndexes().getUInt(new_first), getIndexes().getUInt(j), getDictionary(), nan_direction_hint) != 0)
+            if (getDictionary().compareAt(getIndexes().getUInt(res[new_first]), getIndexes().getUInt(res[j]), getDictionary(), nan_direction_hint) != 0)
             {
                 if (j - new_first > 1)
                     new_ranges.emplace_back(new_first, j);
@@ -387,7 +387,7 @@ void ColumnLowCardinality::updatePermutation(bool reverse, size_t limit, int nan
         auto new_last = limit;
         for (auto j = limit; j < last; ++j)
         {
-            if (getDictionary().compareAt(getIndexes().getUInt(new_first), getIndexes().getUInt(j), getDictionary(), nan_direction_hint) == 0)
+            if (getDictionary().compareAt(getIndexes().getUInt(res[new_first]), getIndexes().getUInt(res[j]), getDictionary(), nan_direction_hint) == 0)
             {
                 std::swap(res[new_last], res[j]);
                 ++new_last;

tests/queries/0_stateless/01456_low_cardinality_sorting_bugfix.reference

+green	2020-08-21 18:46:08
+green	2020-08-21 18:46:07
+green	2020-08-21 18:46:06
+red	2020-08-21 18:46:08
+red	2020-08-21 18:46:07
+red	2020-08-21 18:46:06
+
+
+green	2020-08-21 18:46:08.000
+green	2020-08-21 18:46:07.000
+green	2020-08-21 18:46:06.000
+red	2020-08-21 18:46:08.000
+red	2020-08-21 18:46:07.000
+red	2020-08-21 18:46:06.000
+
+------cast to String----
+
+green	2020-08-21 18:46:08
+green	2020-08-21 18:46:07
+green	2020-08-21 18:46:06
+red	2020-08-21 18:46:08
+red	2020-08-21 18:46:07
+red	2020-08-21 18:46:06
+
+
+green	2020-08-21 18:46:08.000
+green	2020-08-21 18:46:07.000
+green	2020-08-21 18:46:06.000
+red	2020-08-21 18:46:08.000
+red	2020-08-21 18:46:07.000
+red	2020-08-21 18:46:06.000

tests/queries/0_stateless/01456_low_cardinality_sorting_bugfix.sql

+drop  table if exists order_test1;
+
+create table order_test1
+(
+    timestamp DateTime64(3),
+    color     LowCardinality(String)
+) engine = MergeTree() ORDER BY tuple();
+
+insert into order_test1 values ('2020-08-21 18:46:08.000','red')('2020-08-21 18:46:08.000','green');
+insert into order_test1 values ('2020-08-21 18:46:07.000','red')('2020-08-21 18:46:07.000','green');
+insert into order_test1 values ('2020-08-21 18:46:06.000','red')('2020-08-21 18:46:06.000','green');
+
+SELECT color, toDateTime(timestamp) AS second
+FROM order_test1
+GROUP BY color, second
+ORDER BY color ASC, second DESC;
+
+select '';
+select '';
+
+SELECT  color, timestamp
+FROM order_test1
+GROUP BY color, timestamp
+ORDER BY color ASC, timestamp DESC;
+
+select '';
+select '------cast to String----';
+select '';
+
+SELECT cast(color,'String') color, toDateTime(timestamp) AS second
+FROM order_test1
+GROUP BY color, second
+ORDER BY color ASC, second DESC;
+
+select '';
+select '';
+
+SELECT cast(color,'String') color, timestamp
+FROM order_test1
+GROUP BY color, timestamp
+ORDER BY color ASC, timestamp DESC;