fix(plan): bound right dedup memory

pkg/container/hashtable/common.go

@@ -37,6 +37,38 @@ func maxElemCnt(cellCnt, cellSize uint64) uint64 {
 	return cellCnt * 4 / 5
 }
 
+// EstimateInt64HashMapSize returns the cell allocation required by an
+// Int64HashMap for the given number of distinct keys.  Keep this calculation
+// in the hashtable package so planner memory guards follow the same growth and
+// load-factor rules as the runtime implementation.
+func EstimateInt64HashMapSize(cardinality uint64) uint64 {
+	return estimateHashMapSize(cardinality, intCellSize)
+}
+
+// EstimateStringHashMapSize returns the cell allocation required by a
+// StringHashMap for the given number of distinct keys.
+func EstimateStringHashMapSize(cardinality uint64) uint64 {
+	return estimateHashMapSize(cardinality, strCellSize)
+}
+
+func estimateHashMapSize(cardinality, cellSize uint64) uint64 {
+	const maxUint64 = ^uint64(0)
+
+	cellCnt := uint64(kInitialCellCnt)
+	for {
+		if cellCnt > maxUint64/cellSize {
+			return maxUint64
+		}
+		if maxElemCnt(cellCnt, cellSize) >= cardinality {
+			return cellCnt * cellSize
+		}
+		if cellCnt > maxUint64/2 {
+			return maxUint64
+		}
+		cellCnt <<= 1
+	}
+}
+
 func toUnsafePointer[T any](p *T) unsafe.Pointer {
 	return unsafe.Pointer(p)
 }

pkg/container/hashtable/common_test.go

@@ -0,0 +1,34 @@
+// Copyright 2026 Matrix Origin
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hashtable
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestEstimateHashMapSizeFollowsRuntimeGrowth(t *testing.T) {
+	require.Equal(t, uint64(16*1024), EstimateInt64HashMapSize(0))
+	require.Equal(t, uint64(16*1024), EstimateInt64HashMapSize(512))
+	require.Equal(t, uint64(32*1024), EstimateInt64HashMapSize(513))
+
+	require.Equal(t, uint64(32*1024), EstimateStringHashMapSize(0))
+	require.Equal(t, uint64(32*1024), EstimateStringHashMapSize(512))
+	require.Equal(t, uint64(64*1024), EstimateStringHashMapSize(513))
+
+	require.Equal(t, ^uint64(0), EstimateInt64HashMapSize(^uint64(0)))
+	require.Equal(t, ^uint64(0), EstimateStringHashMapSize(^uint64(0)))
+}

pkg/sql/colexec/dedupjoin/join.go

@@ -363,7 +363,7 @@ func (ctr *container) finalize(ap *DedupJoin, proc *process.Process) error {
 	if ctr.matched == nil {
 		return nil
 	}
-	if ap.NumCPU > 1 {
+	if ap.needsFinalizeMerge() {
 		if !ap.IsMerger {
 			msg := &WorkerJoinMsg{matched: ctr.matched}
 			if len(ap.OldColCapturePlaceholderIdxList) > 0 {

pkg/sql/colexec/dedupjoin/join_test.go

@@ -151,6 +151,97 @@ func TestDedupResetClearsBucketState(t *testing.T) {
 	proc.Free()
 }
 
+func TestDedupShuffleWorkersFinalizeTheirOwnPartitions(t *testing.T) {
+	tests := []struct {
+		name        string
+		isShuffle   bool
+		wantOutput  bool
+		wantMessage bool
+	}{
+		{
+			name:        "broadcast worker defers to merger",
+			wantMessage: true,
+		},
+		{
+			name:       "shuffle worker emits local partition",
+			isShuffle:  true,
+			wantOutput: true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			proc := testutil.NewProcessWithMPool(t, "", mpool.MustNewZero())
+			baseline := proc.Mp().CurrNB()
+			typ := types.T_int32.ToType()
+			bat := batch.NewOffHeapWithSize(1)
+			bat.Vecs[0] = vector.NewOffHeapVecWithType(typ)
+			require.NoError(t, vector.AppendFixed(bat.Vecs[0], int32(42), false, proc.Mp()))
+			bat.SetRowCount(1)
+
+			jm := message.NewJoinMap(message.GroupSels{}, nil, nil, nil, []*batch.Batch{bat}, proc.Mp())
+			jm.SetRowCount(1)
+			jm.IncRef(1)
+			matched := &bitmap.Bitmap{}
+			matched.InitWithSize(1)
+			ch := make(chan *WorkerJoinMsg, 1)
+			arg := &DedupJoin{
+				RightTypes:        []types.Type{typ},
+				Result:            []colexec.ResultPos{{Rel: 1, Pos: 0}},
+				OnDuplicateAction: plan.Node_FAIL,
+				NumCPU:            2,
+				IsMerger:          false,
+				IsShuffle:         test.isShuffle,
+				Channel:           ch,
+			}
+			arg.ctr.mp = jm
+			arg.ctr.batches = jm.GetBatches()
+			arg.ctr.batchRowCount = jm.GetRowCount()
+			arg.ctr.matched = matched
+
+			require.NoError(t, arg.ctr.finalize(arg, proc))
+			if test.wantOutput {
+				require.Len(t, arg.ctr.buf, 1)
+				require.Equal(t, []int32{42}, vector.MustFixedColNoTypeCheck[int32](arg.ctr.buf[0].Vecs[0]))
+			} else {
+				require.Nil(t, arg.ctr.buf)
+			}
+			require.Equal(t, test.wantMessage, len(ch) == 1)
+
+			arg.Free(proc, false, nil)
+			require.Equal(t, baseline, proc.Mp().CurrNB())
+			proc.Free()
+		})
+	}
+}
+
+func TestDedupResetNotifiesOnlySharedBuildMerger(t *testing.T) {
+	for _, test := range []struct {
+		name        string
+		isShuffle   bool
+		wantMessage bool
+	}{
+		{name: "broadcast worker notifies merger", wantMessage: true},
+		{name: "shuffle worker owns its partition", isShuffle: true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			proc := testutil.NewProcessWithMPool(t, "", mpool.MustNewZero())
+			ch := make(chan *WorkerJoinMsg, 1)
+			arg := &DedupJoin{
+				NumCPU:    2,
+				IsMerger:  false,
+				IsShuffle: test.isShuffle,
+				Channel:   ch,
+			}
+
+			arg.Reset(proc, false, nil)
+
+			require.Equal(t, test.wantMessage, len(ch) == 1)
+			proc.Free()
+		})
+	}
+}
+
 func TestDedupPrepareFailureCanRetry(t *testing.T) {
 	proc := testutil.NewProcessWithMPool(t, "", mpool.MustNewZero())
 	typ := types.T_int32.ToType()

pkg/sql/colexec/dedupjoin/types.go

@@ -184,9 +184,17 @@ func (dedupJoin *DedupJoin) Release() {
 	}
 }
 
+// needsFinalizeMerge reports whether parallel workers share one build map and
+// therefore must merge their matched state before a single worker emits the
+// build rows. Shuffle workers own disjoint build partitions, so each worker
+// must finalize and emit its partition independently.
+func (dedupJoin *DedupJoin) needsFinalizeMerge() bool {
+	return dedupJoin.NumCPU > 1 && !dedupJoin.IsShuffle
+}
+
 func (dedupJoin *DedupJoin) Reset(proc *process.Process, pipelineFailed bool, err error) {
 	ctr := &dedupJoin.ctr
-	if !ctr.handledLast && dedupJoin.NumCPU > 1 && !dedupJoin.IsMerger {
+	if !ctr.handledLast && dedupJoin.needsFinalizeMerge() && !dedupJoin.IsMerger {
 		dedupJoin.Channel <- nil
 	}
 	if dedupJoin.OpAnalyzer != nil {

pkg/sql/plan/query_builder.go

@@ -2749,6 +2749,7 @@ func (builder *QueryBuilder) createQuery() (*Query, error) {
 		builder.optimizeDistinctAgg(rootID)
 		ReCalcNodeStats(rootID, builder, true, false, true)
 		builder.determineBuildAndProbeSide(rootID, true)
+		builder.disableMemoryUnsafeRightDedup(rootID)
 
 		builder.qry.Steps[i] = rootID
 

pkg/sql/plan/right_dedup_memory_test.go

@@ -0,0 +1,126 @@
+// Copyright 2026 Matrix Origin
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package plan
+
+import (
+	"math"
+	"testing"
+
+	"github.com/matrixorigin/matrixone/pkg/container/types"
+	planpb "github.com/matrixorigin/matrixone/pkg/pb/plan"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDisableMemoryUnsafeRightDedupUsesCombinedMapSize(t *testing.T) {
+	const combinedMapBytes = 64*1024 + 128*1024
+
+	t.Run("combined maps fit", func(t *testing.T) {
+		builder, joins := makeChainedRightDedupBuilder(combinedMapBytes)
+
+		builder.disableMemoryUnsafeRightDedup(4)
+
+		require.True(t, joins[0].IsRightJoin)
+		require.True(t, joins[1].IsRightJoin)
+	})
+
+	t.Run("combined maps exceed budget", func(t *testing.T) {
+		builder, joins := makeChainedRightDedupBuilder(combinedMapBytes - 1)
+
+		builder.disableMemoryUnsafeRightDedup(4)
+
+		require.False(t, joins[0].IsRightJoin)
+		require.False(t, joins[1].IsRightJoin)
+	})
+}
+
+func TestDisableMemoryUnsafeRightDedupHonorsRowThreshold(t *testing.T) {
+	t.Run("combined keys fit", func(t *testing.T) {
+		builder, joins := makeChainedRightDedupBuilder(2201)
+
+		builder.disableMemoryUnsafeRightDedup(4)
+
+		require.True(t, joins[0].IsRightJoin)
+		require.True(t, joins[1].IsRightJoin)
+	})
+
+	t.Run("combined keys reach threshold", func(t *testing.T) {
+		builder, joins := makeChainedRightDedupBuilder(2200)
+
+		builder.disableMemoryUnsafeRightDedup(4)
+
+		require.False(t, joins[0].IsRightJoin)
+		require.False(t, joins[1].IsRightJoin)
+	})
+}
+
+func TestDisableMemoryUnsafeRightDedupRejectsUnknownCardinality(t *testing.T) {
+	tests := []struct {
+		name  string
+		stats *planpb.Stats
+	}{
+		{name: "non-finite", stats: &planpb.Stats{Outcnt: math.NaN()}},
+		{name: "default sentinel", stats: DefaultStats()},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			builder, joins := makeChainedRightDedupBuilder(1 << 30)
+			builder.qry.Nodes[0].Stats = test.stats
+
+			builder.disableMemoryUnsafeRightDedup(4)
+
+			require.False(t, joins[0].IsRightJoin)
+			require.False(t, joins[1].IsRightJoin)
+		})
+	}
+}
+
+func makeChainedRightDedupBuilder(joinSpillMem int64) (*QueryBuilder, []*planpb.Node) {
+	source := &planpb.Node{NodeType: planpb.Node_VALUE_SCAN, Stats: &planpb.Stats{Outcnt: 1000}}
+	targetPK := &planpb.Node{NodeType: planpb.Node_TABLE_SCAN, Stats: &planpb.Stats{Outcnt: 100}}
+	pkDedup := &planpb.Node{
+		NodeType:          planpb.Node_JOIN,
+		JoinType:          planpb.Node_DEDUP,
+		Children:          []int32{1, 0},
+		OnList:            []*planpb.Expr{makeRightDedupEquality(types.T_int64)},
+		OnDuplicateAction: planpb.Node_FAIL,
+		IsRightJoin:       true,
+		Stats:             &planpb.Stats{Outcnt: 100}, // stale pre-swap RIGHT DEDUP estimate
+	}
+	targetUnique := &planpb.Node{NodeType: planpb.Node_TABLE_SCAN, Stats: &planpb.Stats{Outcnt: 100}}
+	uniqueDedup := &planpb.Node{
+		NodeType:          planpb.Node_JOIN,
+		JoinType:          planpb.Node_DEDUP,
+		Children:          []int32{3, 2},
+		OnList:            []*planpb.Expr{makeRightDedupEquality(types.T_varchar)},
+		OnDuplicateAction: planpb.Node_FAIL,
+		IsRightJoin:       true,
+		Stats:             &planpb.Stats{Outcnt: 100},
+	}
+	return &QueryBuilder{
+		qry:          &planpb.Query{Nodes: []*planpb.Node{source, targetPK, pkDedup, targetUnique, uniqueDedup}},
+		joinSpillMem: joinSpillMem,
+	}, []*planpb.Node{pkDedup, uniqueDedup}
+}
+
+func makeRightDedupEquality(typ types.T) *planpb.Expr {
+	planType := planpb.Type{Id: int32(typ)}
+	return &planpb.Expr{
+		Typ: planpb.Type{Id: int32(types.T_bool)},
+		Expr: &planpb.Expr_F{F: &planpb.Function{Args: []*planpb.Expr{
+			{Typ: planType, Expr: &planpb.Expr_Col{Col: &planpb.ColRef{RelPos: 0, ColPos: 0}}},
+			{Typ: planType, Expr: &planpb.Expr_Col{Col: &planpb.ColRef{RelPos: 1, ColPos: 0}}},
+		}}},
+	}
+}

pkg/sql/plan/shuffle.go

@@ -502,8 +502,9 @@ func determineShuffleForJoin(node *plan.Node, builder *QueryBuilder) {
 			}
 		} else {
 			rightChild := builder.qry.Nodes[node.Children[1]]
-			if rightChild.Stats.Outcnt > 320000 {
-				//dedup join always go hash shuffle, optimize this in the future
+			if rightChild.Stats.Outcnt > 320000 && !dedupJoinUsesUnsupportedFloatShuffle(node) {
+				// Large DEDUP joins normally use hash shuffle. FLOAT hash shuffle is
+				// not supported yet, so those joins stay single-CN and spill locally.
 				node.Stats.HashmapStats.Shuffle = true
 				node.Stats.HashmapStats.ShuffleColIdx = 0
 				node.Stats.HashmapStats.ShuffleType = plan.ShuffleType_Hash
@@ -626,6 +627,18 @@ func determineShuffleForJoin(node *plan.Node, builder *QueryBuilder) {
 	}
 }
 
+func dedupJoinUsesUnsupportedFloatShuffle(node *plan.Node) bool {
+	if len(node.OnList) == 0 {
+		return false
+	}
+	condition := node.OnList[0].GetF()
+	if condition == nil || len(condition.Args) == 0 {
+		return false
+	}
+	keyType := types.T(condition.Args[0].Typ.Id)
+	return keyType == types.T_float32 || keyType == types.T_float64
+}
+
 // find mergegroup or mergegroup->filter node
 func dontShuffle(node *plan.Node, builder *QueryBuilder) bool {
 	if node.NodeType == plan.Node_AGG && !node.Stats.HashmapStats.Shuffle {