Revert "Merge pull request #55682 from ClickHouse/revert-35961-decimal-column-improve-get-permutation"

This reverts commit f6dee5fe3c, reversing
changes made to f96bda1deb.

base/base/sort.h

@@ -131,3 +131,29 @@ void sort(RandomIt first, RandomIt last)
     using comparator = std::less<value_type>;
     ::sort(first, last, comparator());
 }
+
+/** Try to fast sort elements for common sorting patterns:
+  * 1. If elements are already sorted.
+  * 2. If elements are already almost sorted.
+  * 3. If elements are already sorted in reverse order.
+  *
+  * Returns true if fast sort was performed or elements were already sorted, false otherwise.
+  */
+template <typename RandomIt, typename Compare>
+bool trySort(RandomIt first, RandomIt last, Compare compare)
+{
+#ifndef NDEBUG
+    ::shuffle(first, last);
+#endif
+
+    ComparatorWrapper<Compare> compare_wrapper = compare;
+    return ::pdqsort_try_sort(first, last, compare_wrapper);
+}
+
+template <typename RandomIt>
+bool trySort(RandomIt first, RandomIt last)
+{
+    using value_type = typename std::iterator_traits<RandomIt>::value_type;
+    using comparator = std::less<value_type>;
+    return ::trySort(first, last, comparator());
+}

contrib/pdqsort/pdqsort.h

@@ -54,8 +54,10 @@ namespace pdqsort_detail {
         block_size = 64,
 
         // Cacheline size, assumes power of two.
-        cacheline_size = 64
+        cacheline_size = 64,
 
+        /// Try sort allowed iterations
+        try_sort_iterations = 3,
     };
 
 #if __cplusplus >= 201103L
@@ -501,6 +503,167 @@ namespace pdqsort_detail {
             leftmost = false;
         }
     }
+
+    template<class Iter, class Compare, bool Branchless>
+    inline bool pdqsort_try_sort_loop(Iter begin,
+        Iter end,
+        Compare comp,
+        size_t bad_allowed,
+        size_t iterations_allowed,
+        bool force_sort = false,
+        bool leftmost = true) {
+        typedef typename std::iterator_traits<Iter>::difference_type diff_t;
+
+        // Use a while loop for tail recursion elimination.
+        while (true) {
+            if (!force_sort && iterations_allowed == 0) {
+                return false;
+            }
+
+            diff_t size = end - begin;
+
+            // Insertion sort is faster for small arrays.
+            if (size < insertion_sort_threshold) {
+                if (leftmost) insertion_sort(begin, end, comp);
+                else unguarded_insertion_sort(begin, end, comp);
+
+                return true;
+            }
+
+            // Choose pivot as median of 3 or pseudomedian of 9.
+            diff_t s2 = size / 2;
+            if (size > ninther_threshold) {
+                sort3(begin, begin + s2, end - 1, comp);
+                sort3(begin + 1, begin + (s2 - 1), end - 2, comp);
+                sort3(begin + 2, begin + (s2 + 1), end - 3, comp);
+                sort3(begin + (s2 - 1), begin + s2, begin + (s2 + 1), comp);
+                std::iter_swap(begin, begin + s2);
+            } else sort3(begin + s2, begin, end - 1, comp);
+
+            // If *(begin - 1) is the end of the right partition of a previous partition operation
+            // there is no element in [begin, end) that is smaller than *(begin - 1). Then if our
+            // pivot compares equal to *(begin - 1) we change strategy, putting equal elements in
+            // the left partition, greater elements in the right partition. We do not have to
+            // recurse on the left partition, since it's sorted (all equal).
+            if (!leftmost && !comp(*(begin - 1), *begin)) {
+                begin = partition_left(begin, end, comp) + 1;
+                continue;
+            }
+
+            // Partition and get results.
+            std::pair<Iter, bool> part_result =
+                Branchless ? partition_right_branchless(begin, end, comp)
+                           : partition_right(begin, end, comp);
+            Iter pivot_pos = part_result.first;
+            bool already_partitioned = part_result.second;
+
+            // Check for a highly unbalanced partition.
+            diff_t l_size = pivot_pos - begin;
+            diff_t r_size = end - (pivot_pos + 1);
+            bool highly_unbalanced = l_size < size / 8 || r_size < size / 8;
+
+            // If we got a highly unbalanced partition we shuffle elements to break many patterns.
+            if (highly_unbalanced) {
+                if (!force_sort) {
+                    return false;
+                }
+
+                // If we had too many bad partitions, switch to heapsort to guarantee O(n log n).
+                if (--bad_allowed == 0) {
+                    std::make_heap(begin, end, comp);
+                    std::sort_heap(begin, end, comp);
+                    return true;
+                }
+
+                if (l_size >= insertion_sort_threshold) {
+                    std::iter_swap(begin,             begin + l_size / 4);
+                    std::iter_swap(pivot_pos - 1, pivot_pos - l_size / 4);
+
+                    if (l_size > ninther_threshold) {
+                        std::iter_swap(begin + 1,         begin + (l_size / 4 + 1));
+                        std::iter_swap(begin + 2,         begin + (l_size / 4 + 2));
+                        std::iter_swap(pivot_pos - 2, pivot_pos - (l_size / 4 + 1));
+                        std::iter_swap(pivot_pos - 3, pivot_pos - (l_size / 4 + 2));
+                    }
+                }
+
+                if (r_size >= insertion_sort_threshold) {
+                    std::iter_swap(pivot_pos + 1, pivot_pos + (1 + r_size / 4));
+                    std::iter_swap(end - 1,                   end - r_size / 4);
+
+                    if (r_size > ninther_threshold) {
+                        std::iter_swap(pivot_pos + 2, pivot_pos + (2 + r_size / 4));
+                        std::iter_swap(pivot_pos + 3, pivot_pos + (3 + r_size / 4));
+                        std::iter_swap(end - 2,             end - (1 + r_size / 4));
+                        std::iter_swap(end - 3,             end - (2 + r_size / 4));
+                    }
+                }
+            } else {
+                // If we were decently balanced and we tried to sort an already partitioned
+                // sequence try to use insertion sort.
+                if (already_partitioned && partial_insertion_sort(begin, pivot_pos, comp)
+                                        && partial_insertion_sort(pivot_pos + 1, end, comp)) {
+                    return true;
+                }
+            }
+
+            // Sort the left partition first using recursion and do tail recursion elimination for
+            // the right-hand partition.
+            if (pdqsort_try_sort_loop<Iter, Compare, Branchless>(begin,
+                pivot_pos,
+                comp,
+                bad_allowed,
+                iterations_allowed - 1,
+                force_sort,
+                leftmost)) {
+                force_sort = true;
+            } else {
+                return false;
+            }
+
+            --iterations_allowed;
+            begin = pivot_pos + 1;
+            leftmost = false;
+        }
+
+        return false;
+    }
+
+    template<class Iter, class Compare, bool Branchless>
+    inline bool pdqsort_try_sort_impl(Iter begin, Iter end, Compare comp, size_t bad_allowed)
+    {
+        typedef typename std::iterator_traits<Iter>::difference_type diff_t;
+
+        static constexpr size_t iterations_allowed = pdqsort_detail::try_sort_iterations;
+        static constexpr size_t num_to_try = 16;
+
+        diff_t size = end - begin;
+
+        if (size > num_to_try * 10)
+        {
+            size_t out_of_order_elements = 0;
+
+            for (size_t i = 1; i < num_to_try; ++i)
+            {
+                diff_t offset = size / num_to_try;
+
+                diff_t prev_position = offset * (i - 1);
+                diff_t curr_position = offset * i;
+                diff_t next_position = offset * (i + 1) - 1;
+
+                bool prev_less_than_curr = comp(*(begin + prev_position), *(begin + curr_position));
+                bool curr_less_than_next = comp(*(begin + curr_position), *(begin + next_position));
+                if ((prev_less_than_curr && curr_less_than_next) || (!prev_less_than_curr && !curr_less_than_next))
+                    continue;
+
+                ++out_of_order_elements;
+                if (out_of_order_elements > iterations_allowed)
+                    return false;
+            }
+        }
+
+        return pdqsort_try_sort_loop<Iter, Compare, Branchless>(begin, end, comp, bad_allowed, iterations_allowed);
+    }
 }
 
 
@@ -538,6 +701,41 @@ inline void pdqsort_branchless(Iter begin, Iter end) {
     pdqsort_branchless(begin, end, std::less<T>());
 }
 
+template<class Iter, class Compare>
+inline bool pdqsort_try_sort(Iter begin, Iter end, Compare comp) {
+    if (begin == end) return true;
+
+#if __cplusplus >= 201103L
+    return pdqsort_detail::pdqsort_try_sort_impl<Iter, Compare,
+        pdqsort_detail::is_default_compare<typename std::decay<Compare>::type>::value &&
+        std::is_arithmetic<typename std::iterator_traits<Iter>::value_type>::value>(
+        begin, end, comp, pdqsort_detail::log2(end - begin));
+#else
+    return pdqsort_detail::pdqsort_try_sort_impl<Iter, Compare, false>(
+        begin, end, comp, pdqsort_detail::log2(end - begin));
+#endif
+}
+
+template<class Iter>
+inline bool pdqsort_try_sort(Iter begin, Iter end) {
+    typedef typename std::iterator_traits<Iter>::value_type T;
+    return pdqsort_try_sort(begin, end, std::less<T>());
+}
+
+template<class Iter, class Compare>
+inline bool pdqsort_try_sort_branchless(Iter begin, Iter end, Compare comp) {
+    if (begin == end) return true;
+
+    return pdqsort_detail::pdqsort_try_sort_impl<Iter, Compare, true>(
+        begin, end, comp, pdqsort_detail::log2(end - begin));
+}
+
+template<class Iter>
+inline bool pdqsort_try_sort_branchless(Iter begin, Iter end) {
+    typedef typename std::iterator_traits<Iter>::value_type T;
+    return pdqsort_try_sort_branchless(begin, end, std::less<T>());
+}
+
 
 #undef PDQSORT_PREFER_MOVE
 

src/Columns/ColumnDecimal.cpp

@@ -4,6 +4,7 @@
 #include <Common/assert_cast.h>
 #include <Common/WeakHash.h>
 #include <Common/HashTable/Hash.h>
+#include <Common/RadixSort.h>
 
 #include <base/unaligned.h>
 #include <base/sort.h>
@@ -15,6 +16,7 @@
 #include <Columns/ColumnDecimal.h>
 #include <Columns/ColumnCompressed.h>
 #include <Columns/MaskOperations.h>
+#include <Columns/RadixSortHelper.h>
 #include <Processors/Transforms/ColumnGathererTransform.h>
 
 
@@ -159,6 +161,59 @@ void ColumnDecimal<T>::getPermutation(IColumn::PermutationSortDirection directio
         return data[lhs] > data[rhs];
     };
 
+    size_t data_size = data.size();
+    res.resize(data_size);
+
+    if (limit >= data_size)
+        limit = 0;
+
+    for (size_t i = 0; i < data_size; ++i)
+        res[i] = i;
+
+    if constexpr (is_arithmetic_v<NativeT> && !is_big_int_v<NativeT>)
+    {
+        if (!limit)
+        {
+            /// A case for radix sort
+            /// LSD RadixSort is stable
+
+            bool reverse = direction == IColumn::PermutationSortDirection::Descending;
+            bool ascending = direction == IColumn::PermutationSortDirection::Ascending;
+            bool sort_is_stable = stability == IColumn::PermutationSortStability::Stable;
+
+            /// TODO: LSD RadixSort is currently not stable if direction is descending
+            bool use_radix_sort = (sort_is_stable && ascending) || !sort_is_stable;
+
+            /// Thresholds on size. Lower threshold is arbitrary. Upper threshold is chosen by the type for histogram counters.
+            if (data_size >= 256 && data_size <= std::numeric_limits<UInt32>::max() && use_radix_sort)
+            {
+                for (size_t i = 0; i < data_size; ++i)
+                    res[i] = i;
+
+                bool try_sort = false;
+
+                if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
+                    try_sort = trySort(res.begin(), res.end(), comparator_ascending);
+                else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
+                    try_sort = trySort(res.begin(), res.end(), comparator_ascending_stable);
+                else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Unstable)
+                    try_sort = trySort(res.begin(), res.end(), comparator_descending);
+                else
+                    try_sort = trySort(res.begin(), res.end(), comparator_descending_stable);
+
+                if (try_sort)
+                    return;
+
+                PaddedPODArray<ValueWithIndex<NativeT>> pairs(data_size);
+                for (UInt32 i = 0; i < static_cast<UInt32>(data_size); ++i)
+                    pairs[i] = {data[i].value, i};
+
+                RadixSort<RadixSortTraits<NativeT>>::executeLSD(pairs.data(), data_size, reverse, res.data());
+                return;
+            }
+        }
+    }
+
     if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
         this->getPermutationImpl(limit, res, comparator_ascending, DefaultSort(), DefaultPartialSort());
     else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
@@ -191,7 +246,37 @@ void ColumnDecimal<T>::updatePermutation(IColumn::PermutationSortDirection direc
         return data[lhs] < data[rhs];
     };
     auto equals_comparator = [this](size_t lhs, size_t rhs) { return data[lhs] == data[rhs]; };
-    auto sort = [](auto begin, auto end, auto pred) { ::sort(begin, end, pred); };
+    auto sort = [&](auto begin, auto end, auto pred)
+    {
+        bool reverse = direction == IColumn::PermutationSortDirection::Descending;
+        bool ascending = direction == IColumn::PermutationSortDirection::Ascending;
+        bool sort_is_stable = stability == IColumn::PermutationSortStability::Stable;
+
+        /// TODO: LSD RadixSort is currently not stable if direction is descending
+        bool use_radix_sort = (sort_is_stable && ascending) || !sort_is_stable;
+        size_t size = end - begin;
+
+        if (size >= 256 && size <= std::numeric_limits<UInt32>::max() && use_radix_sort)
+        {
+            bool try_sort = trySort(begin, end, pred);
+            if (try_sort)
+                return;
+
+            PaddedPODArray<ValueWithIndex<NativeT>> pairs(size);
+            size_t index = 0;
+
+            for (auto * it = begin; it != end; ++it)
+            {
+                pairs[index] = {data[*it].value, static_cast<UInt32>(*it)};
+                ++index;
+            }
+
+            RadixSort<RadixSortTraits<NativeT>>::executeLSD(pairs.data(), size, reverse, res.data());
+            return;
+        }
+
+        ::sort(begin, end, pred);
+    };
     auto partial_sort = [](auto begin, auto mid, auto end, auto pred) { ::partial_sort(begin, mid, end, pred); };
 
     if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)

src/Columns/ColumnVector.cpp

@@ -3,6 +3,7 @@
 #include <Columns/ColumnsCommon.h>
 #include <Columns/ColumnCompressed.h>
 #include <Columns/MaskOperations.h>
+#include <Columns/RadixSortHelper.h>
 #include <Processors/Transforms/ColumnGathererTransform.h>
 #include <IO/WriteHelpers.h>
 #include <Common/Arena.h>
@@ -192,26 +193,6 @@ struct ColumnVector<T>::equals
     bool operator()(size_t lhs, size_t rhs) const { return CompareHelper<T>::equals(parent.data[lhs], parent.data[rhs], nan_direction_hint); }
 };
 
-namespace
-{
-    template <typename T>
-    struct ValueWithIndex
-    {
-        T value;
-        UInt32 index;
-    };
-
-    template <typename T>
-    struct RadixSortTraits : RadixSortNumTraits<T>
-    {
-        using Element = ValueWithIndex<T>;
-        using Result = size_t;
-
-        static T & extractKey(Element & elem) { return elem.value; }
-        static size_t extractResult(Element & elem) { return elem.index; }
-    };
-}
-
 #if USE_EMBEDDED_COMPILER
 
 template <typename T>
@@ -254,35 +235,25 @@ template <typename T>
 void ColumnVector<T>::getPermutation(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
                                     size_t limit, int nan_direction_hint, IColumn::Permutation & res) const
 {
-    size_t s = data.size();
-    res.resize(s);
+    size_t data_size = data.size();
+    res.resize(data_size);
 
-    if (s == 0)
+    if (data_size == 0)
         return;
 
-    if (limit >= s)
+    if (limit >= data_size)
         limit = 0;
 
-    if (limit)
-    {
-        for (size_t i = 0; i < s; ++i)
-            res[i] = i;
+    for (size_t i = 0; i < data_size; ++i)
+        res[i] = i;
 
-        if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
-            ::partial_sort(res.begin(), res.begin() + limit, res.end(), less(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
-            ::partial_sort(res.begin(), res.begin() + limit, res.end(), less_stable(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Unstable)
-            ::partial_sort(res.begin(), res.begin() + limit, res.end(), greater(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Stable)
-            ::partial_sort(res.begin(), res.begin() + limit, res.end(), greater_stable(*this, nan_direction_hint));
-    }
-    else
+    if constexpr (is_arithmetic_v<T> && !is_big_int_v<T>)
     {
-        /// A case for radix sort
-        /// LSD RadixSort is stable
-        if constexpr (is_arithmetic_v<T> && !is_big_int_v<T>)
+        if (!limit)
         {
+            /// A case for radix sort
+            /// LSD RadixSort is stable
+
             bool reverse = direction == IColumn::PermutationSortDirection::Descending;
             bool ascending = direction == IColumn::PermutationSortDirection::Ascending;
             bool sort_is_stable = stability == IColumn::PermutationSortStability::Stable;
@@ -291,13 +262,27 @@ void ColumnVector<T>::getPermutation(IColumn::PermutationSortDirection direction
             bool use_radix_sort = (sort_is_stable && ascending && !std::is_floating_point_v<T>) || !sort_is_stable;
 
             /// Thresholds on size. Lower threshold is arbitrary. Upper threshold is chosen by the type for histogram counters.
-            if (s >= 256 && s <= std::numeric_limits<UInt32>::max() && use_radix_sort)
+            if (data_size >= 256 && data_size <= std::numeric_limits<UInt32>::max() && use_radix_sort)
             {
-                PaddedPODArray<ValueWithIndex<T>> pairs(s);
-                for (UInt32 i = 0; i < static_cast<UInt32>(s); ++i)
+                bool try_sort = false;
+
+                if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
+                    try_sort = trySort(res.begin(), res.end(), less(*this, nan_direction_hint));
+                else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
+                    try_sort = trySort(res.begin(), res.end(), less_stable(*this, nan_direction_hint));
+                else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Unstable)
+                    try_sort = trySort(res.begin(), res.end(), greater(*this, nan_direction_hint));
+                else
+                    try_sort = trySort(res.begin(), res.end(), greater_stable(*this, nan_direction_hint));
+
+                if (try_sort)
+                    return;
+
+                PaddedPODArray<ValueWithIndex<T>> pairs(data_size);
+                for (UInt32 i = 0; i < static_cast<UInt32>(data_size); ++i)
                     pairs[i] = {data[i], i};
 
-                RadixSort<RadixSortTraits<T>>::executeLSD(pairs.data(), s, reverse, res.data());
+                RadixSort<RadixSortTraits<T>>::executeLSD(pairs.data(), data_size, reverse, res.data());
 
                 /// Radix sort treats all NaNs to be greater than all numbers.
                 /// If the user needs the opposite, we must move them accordingly.
@@ -305,9 +290,9 @@ void ColumnVector<T>::getPermutation(IColumn::PermutationSortDirection direction
                 {
                     size_t nans_to_move = 0;
 
-                    for (size_t i = 0; i < s; ++i)
+                    for (size_t i = 0; i < data_size; ++i)
                     {
-                        if (isNaN(data[res[reverse ? i : s - 1 - i]]))
+                        if (isNaN(data[res[reverse ? i : data_size - 1 - i]]))
                             ++nans_to_move;
                         else
                             break;
@@ -315,38 +300,35 @@ void ColumnVector<T>::getPermutation(IColumn::PermutationSortDirection direction
 
                     if (nans_to_move)
                     {
-                        std::rotate(std::begin(res), std::begin(res) + (reverse ? nans_to_move : s - nans_to_move), std::end(res));
+                        std::rotate(std::begin(res), std::begin(res) + (reverse ? nans_to_move : data_size - nans_to_move), std::end(res));
                     }
                 }
+
                 return;
             }
         }
-
-        /// Default sorting algorithm.
-        for (size_t i = 0; i < s; ++i)
-            res[i] = i;
-
-        if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
-            ::sort(res.begin(), res.end(), less(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
-            ::sort(res.begin(), res.end(), less_stable(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Unstable)
-            ::sort(res.begin(), res.end(), greater(*this, nan_direction_hint));
-        else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Stable)
-            ::sort(res.begin(), res.end(), greater_stable(*this, nan_direction_hint));
     }
+
+    if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Unstable)
+        this->getPermutationImpl(limit, res, less(*this, nan_direction_hint), DefaultSort(), DefaultPartialSort());
+    else if (direction == IColumn::PermutationSortDirection::Ascending && stability == IColumn::PermutationSortStability::Stable)
+        this->getPermutationImpl(limit, res, less_stable(*this, nan_direction_hint), DefaultSort(), DefaultPartialSort());
+    else if (direction == IColumn::PermutationSortDirection::Descending && stability == IColumn::PermutationSortStability::Unstable)
+        this->getPermutationImpl(limit, res, greater(*this, nan_direction_hint), DefaultSort(), DefaultPartialSort());
+    else
+        this->getPermutationImpl(limit, res, greater_stable(*this, nan_direction_hint), DefaultSort(), DefaultPartialSort());
 }
 
 template <typename T>
 void ColumnVector<T>::updatePermutation(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
                                     size_t limit, int nan_direction_hint, IColumn::Permutation & res, EqualRanges & equal_ranges) const
 {
-    bool reverse = direction == IColumn::PermutationSortDirection::Descending;
-    bool ascending = direction == IColumn::PermutationSortDirection::Ascending;
-    bool sort_is_stable = stability == IColumn::PermutationSortStability::Stable;
-
     auto sort = [&](auto begin, auto end, auto pred)
     {
+        bool reverse = direction == IColumn::PermutationSortDirection::Descending;
+        bool ascending = direction == IColumn::PermutationSortDirection::Ascending;
+        bool sort_is_stable = stability == IColumn::PermutationSortStability::Stable;
+
         /// A case for radix sort
         if constexpr (is_arithmetic_v<T> && !is_big_int_v<T>)
         {
@@ -357,6 +339,10 @@ void ColumnVector<T>::updatePermutation(IColumn::PermutationSortDirection direct
             /// Thresholds on size. Lower threshold is arbitrary. Upper threshold is chosen by the type for histogram counters.
             if (size >= 256 && size <= std::numeric_limits<UInt32>::max() && use_radix_sort)
             {
+                bool try_sort = trySort(begin, end, pred);
+                if (try_sort)
+                    return;
+
                 PaddedPODArray<ValueWithIndex<T>> pairs(size);
                 size_t index = 0;
 

src/Columns/RadixSortHelper.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <Common/RadixSort.h>
+
+namespace DB
+{
+
+template <typename T>
+struct ValueWithIndex
+{
+    T value;
+    UInt32 index;
+};
+
+template <typename T>
+struct RadixSortTraits : RadixSortNumTraits<T>
+{
+    using Element = ValueWithIndex<T>;
+    using Result = size_t;
+
+    static T & extractKey(Element & elem) { return elem.value; }
+    static size_t extractResult(Element & elem) { return elem.index; }
+};
+
+}

tests/performance/merge_tree_insert.xml

@@ -18,15 +18,29 @@
                 <value>merge_tree_insert_6</value>
             </values>
         </substitution>
+
+        <substitution>
+            <name>decimal_primary_key_table_name</name>
+            <values>
+                <value>merge_tree_insert_7</value>
+                <value>merge_tree_insert_8</value>
+                <value>merge_tree_insert_9</value>
+            </values>
+        </substitution>
     </substitutions>
 
     <create_query>CREATE TABLE merge_tree_insert_1 (value_1 UInt64, value_2 UInt64, value_3 UInt64) ENGINE = MergeTree ORDER BY (value_1)</create_query>
     <create_query>CREATE TABLE merge_tree_insert_2 (value_1 UInt64, value_2 UInt64, value_3 UInt64) ENGINE = MergeTree ORDER BY (value_1, value_2)</create_query>
     <create_query>CREATE TABLE merge_tree_insert_3 (value_1 UInt64, value_2 UInt64, value_3 UInt64) ENGINE = MergeTree ORDER BY (value_1, value_2, value_3)</create_query>
+
     <create_query>CREATE TABLE merge_tree_insert_4 (value_1 String, value_2 String, value_3 String) ENGINE = MergeTree ORDER BY (value_1)</create_query>
     <create_query>CREATE TABLE merge_tree_insert_5 (value_1 String, value_2 String, value_3 String) ENGINE = MergeTree ORDER BY (value_1, value_2)</create_query>
     <create_query>CREATE TABLE merge_tree_insert_6 (value_1 String, value_2 String, value_3 String) ENGINE = MergeTree ORDER BY (value_1, value_2, value_3)</create_query>
 
+    <create_query>CREATE TABLE merge_tree_insert_7 (value_1 Decimal64(8), value_2  Decimal64(8), value_3  Decimal64(8)) ENGINE = MergeTree ORDER BY (value_1)</create_query>
+    <create_query>CREATE TABLE merge_tree_insert_8 (value_1 Decimal64(8), value_2  Decimal64(8), value_3  Decimal64(8)) ENGINE = MergeTree ORDER BY (value_1, value_2)</create_query>
+    <create_query>CREATE TABLE merge_tree_insert_9 (value_1 Decimal64(8), value_2  Decimal64(8), value_3  Decimal64(8)) ENGINE = MergeTree ORDER BY (value_1, value_2, value_3)</create_query>
+
     <query>INSERT INTO {integer_primary_key_table_name} SELECT rand64(0), rand64(1), rand64(2) FROM system.numbers LIMIT 500000</query>
     <query>INSERT INTO {integer_primary_key_table_name} SELECT rand64(0), rand64(1), rand64(2) FROM system.numbers LIMIT 1000000</query>
     <query>INSERT INTO {integer_primary_key_table_name} SELECT rand64(0), rand64(1), rand64(2) FROM system.numbers LIMIT 1500000</query>
@@ -35,7 +49,12 @@
     <query>INSERT INTO {string_primary_key_table_name} SELECT toString(rand64(0)), toString(rand64(1)), toString(rand64(2)) FROM system.numbers LIMIT 1000000</query>
     <query>INSERT INTO {string_primary_key_table_name} SELECT toString(rand64(0)), toString(rand64(1)), toString(rand64(2)) FROM system.numbers LIMIT 1500000</query>
 
+    <query>INSERT INTO {decimal_primary_key_table_name} SELECT rand64(0) % 1000000, rand64(1) % 1500000, rand64(2) % 2000000 FROM system.numbers LIMIT 500000</query>
+    <query>INSERT INTO {decimal_primary_key_table_name} SELECT rand64(0) % 1000000, rand64(1) % 1500000, rand64(2) % 2000000 FROM system.numbers LIMIT 1000000</query>
+    <query>INSERT INTO {decimal_primary_key_table_name} SELECT rand64(0) % 1000000, rand64(1) % 1500000, rand64(2) % 2000000 FROM system.numbers LIMIT 1500000</query>
+
     <drop_query>DROP TABLE IF EXISTS {integer_primary_key_table_name}</drop_query>
     <drop_query>DROP TABLE IF EXISTS {string_primary_key_table_name}</drop_query>
+    <drop_query>DROP TABLE IF EXISTS {decimal_primary_key_table_name}</drop_query>
 
 </test>

tests/performance/sort_patterns.xml

@@ -0,0 +1,28 @@
+<test>
+    <substitutions>
+        <substitution>
+            <name>integer_type</name>
+            <values>
+                <value>UInt32</value>
+                <value>UInt64</value>
+            </values>
+        </substitution>
+        <substitution>
+            <name>sort_expression</name>
+            <values>
+                <value>key</value>
+                <value>key, value</value>
+                <value>key DESC</value>
+                <value>key DESC, value DESC</value>
+            </values>
+        </substitution>
+    </substitutions>
+
+    <create_query>CREATE TABLE sequential_{integer_type} (key {integer_type}, value {integer_type}) Engine = Memory</create_query>
+
+    <fill_query>INSERT INTO sequential_{integer_type} SELECT number, number FROM numbers(500000000)</fill_query>
+
+    <query>SELECT key, value FROM sequential_{integer_type} ORDER BY {sort_expression} FORMAT Null</query>
+
+    <drop_query>DROP TABLE IF EXISTS sequential_{integer_type}</drop_query>
+</test>