Merge pull request #59731 from kitaisreal/asof-join-try-sort-with-radix-sort

ASOF JOIN use trySort with RadixSort

src/Common/RadixSort.h

@@ -15,6 +15,7 @@
 
 #include <base/bit_cast.h>
 #include <base/extended_types.h>
+#include <base/sort.h>
 #include <Core/Defines.h>
 
 
@@ -114,6 +115,11 @@ struct RadixSortFloatTraits
     {
         return x < y;
     }
+
+    static bool greater(Key x, Key y)
+    {
+        return x > y;
+    }
 };
 
 
@@ -148,6 +154,11 @@ struct RadixSortUIntTraits
     {
         return x < y;
     }
+
+    static bool greater(Key x, Key y)
+    {
+        return x > y;
+    }
 };
 
 
@@ -182,6 +193,11 @@ struct RadixSortIntTraits
     {
         return x < y;
     }
+
+    static bool greater(Key x, Key y)
+    {
+        return x > y;
+    }
 };
 
 
@@ -214,6 +230,22 @@ private:
     static KeyBits keyToBits(Key x) { return bit_cast<KeyBits>(x); }
     static Key bitsToKey(KeyBits x) { return bit_cast<Key>(x); }
 
+    struct LessComparator
+    {
+        ALWAYS_INLINE bool operator()(Element & lhs, Element & rhs)
+        {
+            return Traits::less(Traits::extractKey(lhs), Traits::extractKey(rhs));
+        }
+    };
+
+    struct GreaterComparator
+    {
+        ALWAYS_INLINE bool operator()(Element & lhs, Element & rhs)
+        {
+            return Traits::greater(Traits::extractKey(lhs), Traits::extractKey(rhs));
+        }
+    };
+
     static ALWAYS_INLINE KeyBits getPart(size_t N, KeyBits x)
     {
         if (Traits::Transform::transform_is_simple)
@@ -504,6 +536,24 @@ private:
             radixSortMSDInternal<PASS>(arr, size, limit);
     }
 
+    template <bool DIRECT_WRITE_TO_DESTINATION, typename Comparator>
+    static void executeLSDWithTrySortInternal(Element * arr, size_t size, bool reverse, Comparator comparator, Result * destination)
+    {
+        bool try_sort = ::trySort(arr, arr + size, comparator);
+        if (try_sort)
+        {
+            if constexpr (DIRECT_WRITE_TO_DESTINATION)
+            {
+                for (size_t i = 0; i < size; ++i)
+                    destination[i] = Traits::extractResult(arr[i]);
+            }
+
+            return;
+        }
+
+        radixSortLSDInternal<DIRECT_WRITE_TO_DESTINATION>(arr, size, reverse, destination);
+    }
+
 public:
     /** Least significant digit radix sort (stable).
       * This function will sort inplace (modify 'arr')
@@ -529,6 +579,38 @@ public:
         radixSortLSDInternal<true>(arr, size, reverse, destination);
     }
 
+    /** Tries to fast sort elements for common sorting patterns (unstable).
+      * If fast sort cannot be performed, execute least significant digit radix sort.
+      */
+    static void executeLSDWithTrySort(Element * arr, size_t size)
+    {
+        return executeLSDWithTrySort(arr, size, false);
+    }
+
+    static void executeLSDWithTrySort(Element * arr, size_t size, bool reverse)
+    {
+        return executeLSDWithTrySort(arr, size, reverse, nullptr);
+    }
+
+    static void executeLSDWithTrySort(Element * arr, size_t size, bool reverse, Result * destination)
+    {
+        if (reverse)
+        {
+
+            if (destination)
+                return executeLSDWithTrySortInternal<true>(arr, size, reverse, GreaterComparator(), destination);
+            else
+                return executeLSDWithTrySortInternal<false>(arr, size, reverse, GreaterComparator(), destination);
+        }
+        else
+        {
+            if (destination)
+                return executeLSDWithTrySortInternal<true>(arr, size, reverse, LessComparator(), destination);
+            else
+                return executeLSDWithTrySortInternal<false>(arr, size, reverse, LessComparator(), destination);
+        }
+    }
+
     /* Most significant digit radix sort
      * Is not stable, but allows partial sorting.
      * And it's more cache-friendly and usually faster than LSD variant.

src/Interpreters/RowRefs.cpp

@@ -175,45 +175,42 @@ private:
     // the array becomes immutable
     void sort()
     {
-        if (!sorted.load(std::memory_order_acquire))
+        if (sorted.load(std::memory_order_acquire))
+            return;
+
+        std::lock_guard<std::mutex> l(lock);
+
+        if (sorted.load(std::memory_order_relaxed))
+            return;
+
+        if constexpr (std::is_arithmetic_v<TKey> && !std::is_floating_point_v<TKey>)
         {
-            std::lock_guard<std::mutex> l(lock);
-
-            if (!sorted.load(std::memory_order_relaxed))
+            if (likely(entries.size() > 256))
             {
-                if constexpr (std::is_arithmetic_v<TKey> && !std::is_floating_point_v<TKey>)
+                struct RadixSortTraits : RadixSortNumTraits<TKey>
                 {
-                    if (likely(entries.size() > 256))
-                    {
-                        struct RadixSortTraits : RadixSortNumTraits<TKey>
-                        {
-                            using Element = Entry;
-                            using Result = Element;
+                    using Element = Entry;
+                    using Result = Element;
 
-                            static TKey & extractKey(Element & elem) { return elem.value; }
-                            static Result extractResult(Element & elem) { return elem; }
-                        };
-
-                        if constexpr (is_descending)
-                            RadixSort<RadixSortTraits>::executeLSD(entries.data(), entries.size(), true);
-                        else
-                            RadixSort<RadixSortTraits>::executeLSD(entries.data(), entries.size(), false);
-
-                        sorted.store(true, std::memory_order_release);
-                        return;
-                    }
-                }
-
-                if constexpr (is_descending)
-                    ::sort(entries.begin(), entries.end(), GreaterEntryOperator());
-                else
-                    ::sort(entries.begin(), entries.end(), LessEntryOperator());
+                    static TKey & extractKey(Element & elem) { return elem.value; }
+                    static Result extractResult(Element & elem) { return elem; }
+                };
 
+                RadixSort<RadixSortTraits>::executeLSDWithTrySort(entries.data(), entries.size(), is_descending /*reverse*/);
                 sorted.store(true, std::memory_order_release);
+                return;
             }
         }
+
+        if constexpr (is_descending)
+            ::sort(entries.begin(), entries.end(), GreaterEntryOperator());
+        else
+            ::sort(entries.begin(), entries.end(), LessEntryOperator());
+
+        sorted.store(true, std::memory_order_release);
     }
 };
+
 }
 
 AsofRowRefs createAsofRowRef(TypeIndex type, ASOFJoinInequality inequality)

tests/performance/asof.xml

@@ -43,6 +43,13 @@
     </query>
 
     <substitutions>
+        <substitution>
+            <name>num_unique_sessions</name>
+            <values>
+                <value>1000</value>
+                <value>1000000</value>
+            </values>
+        </substitution>
         <substitution>
             <name>num_rows</name>
             <values>
@@ -56,15 +63,15 @@
         FROM
         (
             SELECT
-                number AS id,
-                number AS visitor_id
+                (number % {num_unique_sessions}) AS visitor_id,
+                number AS id
             FROM system.numbers
             LIMIT {num_rows}
         ) AS sessions
         ASOF LEFT JOIN
         (
             SELECT
-                number AS visitor_id,
+                (number % {num_unique_sessions}) AS visitor_id,
                 number AS starting_session_id
             FROM system.numbers
             LIMIT {num_rows}