Fix Window operator with NaN as the frame bound (#11293)

Summary:

NaN could appear as the frame bound of k-range frames in window 
operations. When NaN appear in either of the frame bounds, the window 
operation should return NULL at this row.

This diff fixes #11213.

Reviewed By: xiaoxmeng

Differential Revision: D64510519

velox/exec/RowContainer.h

@@ -769,10 +769,21 @@ class RowContainer {
     return (row[nullByte] & nullMask) != 0;
   }
 
-  static inline bool isNullAt(const char* row, RowColumn rowColumn) {
+  static inline bool isNullAt(const char* row, const RowColumn& rowColumn) {
     return (row[rowColumn.nullByte()] & rowColumn.nullMask()) != 0;
   }
 
+  /// Returns true if the value at rowColumn in row is NaN.
+  template <
+      typename T,
+      std::enable_if_t<std::is_floating_point_v<T>, int32_t> = 0>
+  static inline bool isNanAt(const char* row, const RowColumn& rowColumn) {
+    if (isNullAt(row, rowColumn.nullByte(), rowColumn.nullMask())) {
+      return false;
+    }
+    return std::isnan(valueAt<T>(row, rowColumn.offset()));
+  }
+
   /// Creates a container to store a partition number for each row in this row
   /// container. This is used by parallel join build which is responsible for
   /// filling this. This function also marks this row container as immutable

velox/exec/Window.cpp

@@ -409,7 +409,8 @@ void Window::updateFrameBounds(
     const vector_size_t numRows,
     const vector_size_t* rawPeerStarts,
     const vector_size_t* rawPeerEnds,
-    vector_size_t* rawFrameBounds) {
+    vector_size_t* rawFrameBounds,
+    SelectivityVector& validFrames) {
   const auto windowType = windowFrame.type;
   const auto boundType =
       isStartBound ? windowFrame.startType : windowFrame.endType;
@@ -447,7 +448,8 @@ void Window::updateFrameBounds(
             startRow,
             numRows,
             rawPeerBuffer,
-            rawFrameBounds);
+            rawFrameBounds,
+            validFrames);
       }
       break;
     }
@@ -463,7 +465,8 @@ void Window::updateFrameBounds(
             startRow,
             numRows,
             rawPeerBuffer,
-            rawFrameBounds);
+            rawFrameBounds,
+            validFrames);
       }
       break;
     }
@@ -486,6 +489,9 @@ void computeValidFrames(
     vector_size_t* rawFrameEnds,
     SelectivityVector& validFrames) {
   for (auto i = 0; i < numRows; ++i) {
+    if (!validFrames.isValid(i)) {
+      continue;
+    }
     const vector_size_t frameStart = rawFrameStarts[i];
     const vector_size_t frameEnd = rawFrameEnds[i];
     // All valid frames require frameStart <= frameEnd to define the frame rows.
@@ -545,15 +551,17 @@ void Window::computePeerAndFrameBuffers(
         numRows,
         rawPeerStarts,
         rawPeerEnds,
-        rawFrameStarts[i]);
+        rawFrameStarts[i],
+        validFrames_[i]);
     updateFrameBounds(
         windowFrame,
         false,
         startRow,
         numRows,
         rawPeerStarts,
         rawPeerEnds,
-        rawFrameEnds[i]);
+        rawFrameEnds[i],
+        validFrames_[i]);
     if (windowFrames_[i].start || windowFrames_[i].end) {
       // k preceding and k following bounds can be problematic. They can go over
       // the partition limits or result in empty frames. Fix the frame

velox/exec/Window.h

@@ -149,14 +149,18 @@ class Window : public Operator {
       vector_size_t numRows,
       vector_size_t* rawFrameBounds);
 
+  // Populate frame bounds in the current partition into rawFrameBounds.
+  // Unselect rows from validFrames where the frame bounds are NaN that are
+  // invalid.
   void updateFrameBounds(
       const WindowFrame& windowFrame,
       const bool isStartBound,
       const vector_size_t startRow,
       const vector_size_t numRows,
       const vector_size_t* rawPeerStarts,
       const vector_size_t* rawPeerEnds,
-      vector_size_t* rawFrameBounds);
+      vector_size_t* rawFrameBounds,
+      SelectivityVector& validFrames);
 
   const vector_size_t numInputColumns_;
 

velox/exec/WindowPartition.cpp

@@ -349,6 +349,7 @@ vector_size_t WindowPartition::linearSearchFrameValue(
   return end == numRows() ? numRows() + 1 : -1;
 }
 
+template <typename T>
 void WindowPartition::updateKRangeFrameBounds(
     bool firstMatch,
     bool isPreceding,
@@ -357,21 +358,34 @@ void WindowPartition::updateKRangeFrameBounds(
     vector_size_t numRows,
     column_index_t frameColumn,
     const vector_size_t* rawPeerBounds,
-    vector_size_t* rawFrameBounds) const {
+    vector_size_t* rawFrameBounds,
+    SelectivityVector& validFrames) const {
   column_index_t orderByColumn = sortKeyInfo_[0].first;
   column_index_t mappedFrameColumn = inputMapping_[frameColumn];
 
   vector_size_t start = 0;
   vector_size_t end;
   // frameColumn is a column index into the original input rows, while
-  // orderByColumn is a column index into rows in data_ after the columns are
-  // reordered as per inputMapping_.
+  // orderByColumn and mappedFrameColumn are column indices into rows in data_
+  // after the columns are reordered as per inputMapping_.
   VELOX_DEBUG_ONLY RowColumn frameRowColumn = columns_[frameColumn];
   RowColumn orderByRowColumn = data_->columnAt(orderByColumn);
+  RowColumn mappedFrameRowColumn = data_->columnAt(mappedFrameColumn);
   for (auto i = 0; i < numRows; i++) {
     auto currentRow = startRow + i;
     auto* partitionRow = partition_[currentRow];
 
+    // Mark the frame invalid if the frame bound is NaN, except if NaN in the
+    // frame column is derived from NaN in the order-by column.
+    // https://github.com/facebookincubator/velox/pull/11293#issuecomment-2475391888
+    if constexpr (std::is_floating_point_v<T>) {
+      if (data_->isNanAt<T>(partitionRow, mappedFrameRowColumn) &&
+          !data_->isNanAt<T>(partitionRow, orderByRowColumn)) {
+        validFrames.setValid(currentRow, false);
+        continue;
+      }
+    }
+
     // The user is expected to set the frame column equal to NULL when the
     // ORDER BY value is NULL and not in any other case. Validate this
     // assumption.
@@ -423,20 +437,48 @@ void WindowPartition::computeKRangeFrameBounds(
     vector_size_t startRow,
     vector_size_t numRows,
     const vector_size_t* rawPeerBuffer,
-    vector_size_t* rawFrameBounds) const {
+    vector_size_t* rawFrameBounds,
+    SelectivityVector& validFrames) const {
   CompareFlags flags;
   flags.ascending = sortKeyInfo_[0].second.isAscending();
   flags.nullsFirst = sortKeyInfo_[0].second.isNullsFirst();
+
   // Start bounds require first match. End bounds require last match.
-  updateKRangeFrameBounds(
-      isStartBound,
-      isPreceding,
-      flags,
-      startRow,
-      numRows,
-      frameColumn,
-      rawPeerBuffer,
-      rawFrameBounds);
+  const auto frameType = data_->columnTypes()[inputMapping_[frameColumn]];
+  if (frameType->isReal()) {
+    updateKRangeFrameBounds<float>(
+        isStartBound,
+        isPreceding,
+        flags,
+        startRow,
+        numRows,
+        frameColumn,
+        rawPeerBuffer,
+        rawFrameBounds,
+        validFrames);
+  } else if (frameType->isDouble()) {
+    updateKRangeFrameBounds<double>(
+        isStartBound,
+        isPreceding,
+        flags,
+        startRow,
+        numRows,
+        frameColumn,
+        rawPeerBuffer,
+        rawFrameBounds,
+        validFrames);
+  } else {
+    updateKRangeFrameBounds<void>(
+        isStartBound,
+        isPreceding,
+        flags,
+        startRow,
+        numRows,
+        frameColumn,
+        rawPeerBuffer,
+        rawFrameBounds,
+        validFrames);
+  }
 }
 
 } // namespace facebook::velox::exec

velox/exec/WindowPartition.h

@@ -158,14 +158,18 @@ class WindowPartition {
   /// @param numRows number of rows to compute buffer for.
   /// @param rawPeerStarts buffer of peer row values for each row. If the frame
   /// column is null, then its peer row value is the frame boundary.
+  /// @param validFrames SelectivityVector to keep track of valid frames.
+  /// This function unselect rows in validFrames where the frame bounds are NaN
+  /// that are invalid.
   void computeKRangeFrameBounds(
       bool isStartBound,
       bool isPreceding,
       column_index_t frameColumn,
       vector_size_t startRow,
       vector_size_t numRows,
       const vector_size_t* rawPeerStarts,
-      vector_size_t* rawFrameBounds) const;
+      vector_size_t* rawFrameBounds,
+      SelectivityVector& validFrames) const;
 
  private:
   WindowPartition(
@@ -216,7 +220,13 @@ class WindowPartition {
       column_index_t frameColumn,
       const CompareFlags& flags) const;
 
-  // Iterates over 'numBlockRows' and searches frame value for each row.
+  /// Iterates over 'numBlockRows' and searches frame value for each row.
+  /// @tparam T The C++ type of the order-by and frame columns. When T is float
+  /// or double, this method checks for rows with NaN frame bound(s) but non-NaN
+  /// order-by value. These frames are invalid and we unselect these rows from
+  /// 'validFrames'. If the order-by and frame columns are not of floating-point
+  /// types, T should be set to void.
+  template <typename T>
   void updateKRangeFrameBounds(
       bool firstMatch,
       bool isPreceding,
@@ -225,7 +235,8 @@ class WindowPartition {
       vector_size_t numRows,
       column_index_t frameColumn,
       const vector_size_t* rawPeerBounds,
-      vector_size_t* rawFrameBounds) const;
+      vector_size_t* rawFrameBounds,
+      SelectivityVector& validFrames) const;
 
   // Indicates if this is a partial partition for RowStreamWindowBuild
   // processing.

velox/exec/tests/RowContainerTest.cpp

@@ -2290,3 +2290,53 @@ TEST_F(RowContainerTest, customComparisonRow) {
             expectedOrder, BIGINT_TYPE_WITH_CUSTOM_COMPARISON())});
       });
 }
+
+TEST_F(RowContainerTest, isNanAt) {
+  const auto kNan = std::numeric_limits<double>::quiet_NaN();
+  const auto kNanF = std::numeric_limits<float>::quiet_NaN();
+  auto rowVector = makeRowVector({
+      makeFlatVector<float>({kNanF, 0.2, 0.3, 0.4}),
+      makeFlatVector<double>({0.1, kNan, 0.3, 0.4}),
+      makeFlatVector<float>({0.1, 0.2, kNanF, 0.4}),
+      makeFlatVector<double>({0.1, 0.2, 0.3, kNan}),
+  });
+  const auto kNumRows = rowVector->size();
+
+  auto rowContainer =
+      makeRowContainer({REAL(), DOUBLE()}, {REAL(), DOUBLE()}, false);
+  std::vector<char*> rows;
+  rows.reserve(kNumRows);
+
+  SelectivityVector allRows(kNumRows);
+  for (size_t i = 0; i < kNumRows; i++) {
+    auto row = rowContainer->newRow();
+    rows.push_back(row);
+  }
+  for (int j = 0; j < rowContainer->columnTypes().size(); ++j) {
+    DecodedVector decoded(*rowVector->childAt(j), allRows);
+    rowContainer->store(decoded, folly::Range(rows.data(), kNumRows), j);
+  }
+
+  for (int i = 0; i < kNumRows; ++i) {
+    const auto* row = rows[i];
+    for (int j = 0; j < 4; ++j) {
+      if (i % 2 == 0) {
+        if (i == j) {
+          EXPECT_TRUE(
+              rowContainer->isNanAt<float>(row, rowContainer->columnAt(j)));
+        } else {
+          EXPECT_FALSE(
+              rowContainer->isNanAt<float>(row, rowContainer->columnAt(j)));
+        }
+      } else {
+        if (i == j) {
+          EXPECT_TRUE(
+              rowContainer->isNanAt<double>(row, rowContainer->columnAt(j)));
+        } else {
+          EXPECT_FALSE(
+              rowContainer->isNanAt<double>(row, rowContainer->columnAt(j)));
+        }
+      }
+    }
+  }
+}

velox/exec/tests/WindowTest.cpp

@@ -692,5 +692,65 @@ DEBUG_ONLY_TEST_F(WindowTest, reserveMemorySort) {
   }
 }
 
+TEST_F(WindowTest, NaNFrameBound) {
+  const auto kNan = std::numeric_limits<double>::quiet_NaN();
+  auto data = makeRowVector(
+      {"c0", "s0", "off0", "off1"},
+      {
+          makeFlatVector<int64_t>({1, 2, 3, 4}),
+          makeFlatVector<double>({1.0, 2.0, 3.0, kNan}),
+          makeFlatVector<double>({0.1, 2.0, 1.9, kNan}),
+          makeFlatVector<double>({kNan, 2.0, kNan, kNan}),
+      });
+
+  const auto makeFrames = [](const std::string& call) {
+    std::vector<std::string> frames;
+
+    std::vector<std::string> orders{"asc", "desc"};
+    std::vector<std::string> bounds{"preceding", "following"};
+    for (const std::string& order : orders) {
+      for (const std::string& startBound : bounds) {
+        for (const std::string& endBound : bounds) {
+          // Frames starting from following and ending at preceding are not
+          // allowed.
+          if (startBound == "following" && endBound == "preceding") {
+            continue;
+          }
+          frames.push_back(fmt::format(
+              "{} over (order by s0 {} range between off0 {} and off1 {})",
+              call,
+              order,
+              startBound,
+              endBound));
+          frames.push_back(fmt::format(
+              "{} over (order by s0 {} range between off1 {} and off0 {})",
+              call,
+              order,
+              startBound,
+              endBound));
+        }
+      }
+    }
+    return frames;
+  };
+
+  auto expected = makeRowVector(
+      {makeNullableFlatVector<int64_t>({std::nullopt, 2, std::nullopt, 4})});
+  for (const auto& frame : makeFrames("sum(c0)")) {
+    auto plan =
+        PlanBuilder().values({data}).window({frame}).project({"w0"}).planNode();
+    AssertQueryBuilder(plan).assertResults(expected);
+  }
+
+  // rank() should not be affected by the frames, so added this test to ensure
+  // rank() produces correct results even if the frame bounds contain NaN.
+  expected = makeRowVector({makeFlatVector<int64_t>({1, 2, 3, 4})});
+  for (const auto& frame : makeFrames("rank()")) {
+    auto plan =
+        PlanBuilder().values({data}).window({frame}).project({"w0"}).planNode();
+    AssertQueryBuilder(plan).assertResults(expected);
+  }
+}
+
 } // namespace
 } // namespace facebook::velox::exec