opt: unexport relational stats to avoid accidental copies

Previously, the `props.Statistics` field of `props.Relational` was exported.
This made it easy to accidentally copy it, which could show up on heap profiles
because `props.Statistics` is a fairly large struct.

This patch unexports `props.Statistics` and exposes a `Relational.Statistics()`
method that returns a pointer to the field. This changes the default behavior
to reference the struct, rather than copying it, in order to prevent accidental
copies in the future (and revert the current ones).

Release note: None

pkg/sql/opt/exec/execbuilder/builder.go

@@ -226,7 +226,7 @@ func (b *Builder) Build() (_ exec.Plan, err error) {
 		return nil, err
 	}
 
-	rootRowCount := int64(b.e.(memo.RelExpr).Relational().Stats.RowCountIfAvailable())
+	rootRowCount := int64(b.e.(memo.RelExpr).Relational().Statistics().RowCountIfAvailable())
 	return b.factory.ConstructPlan(plan.root, b.subqueries, b.cascades, b.checks, rootRowCount)
 }
 

pkg/sql/opt/exec/execbuilder/cascades.go

@@ -241,7 +241,7 @@ func (cb *cascadeBuilder) planCascade(
 			Min: uint32(numBufferedRows),
 			Max: uint32(numBufferedRows),
 		}
-		bindingProps.Stats = props.Statistics{
+		*bindingProps.Statistics() = props.Statistics{
 			Available: true,
 			RowCount:  float64(numBufferedRows),
 		}

pkg/sql/opt/exec/execbuilder/relational.go

@@ -388,7 +388,7 @@ func (b *Builder) buildRelational(e memo.RelExpr) (execPlan, error) {
 // ExplainFactory and annotates the node with more information if so.
 func (b *Builder) maybeAnnotateWithEstimates(node exec.Node, e memo.RelExpr) {
 	if ef, ok := b.factory.(exec.ExplainFactory); ok {
-		stats := &e.Relational().Stats
+		stats := e.Relational().Statistics()
 		val := exec.EstimatedStats{
 			TableStatsAvailable: stats.Available,
 			RowCount:            stats.RowCount,
@@ -616,8 +616,8 @@ func (b *Builder) scanParams(
 	// been removed by DetachMemo. Update that function if the column stats are
 	// needed here in the future.
 	var rowCount float64
-	if relProps.Stats.Available {
-		rowCount = relProps.Stats.RowCount
+	if relProps.Statistics().Available {
+		rowCount = relProps.Statistics().RowCount
 	}
 
 	if scan.PartitionConstrainedScan {
@@ -715,7 +715,7 @@ func (b *Builder) buildScan(scan *memo.ScanExpr) (execPlan, error) {
 
 	// Save if we planned a full table/index scan on the builder so that the
 	// planner can be made aware later. We only do this for non-virtual tables.
-	stats := scan.Relational().Stats
+	stats := scan.Relational().Statistics()
 	if !tab.IsVirtualTable() && isUnfiltered {
 		large := !stats.Available || stats.RowCount > b.evalCtx.SessionData().LargeFullScanRows
 		if scan.Index == cat.PrimaryIndex {
@@ -1167,8 +1167,8 @@ func (b *Builder) buildHashJoin(join memo.RelExpr) (execPlan, error) {
 		// it during the costing.
 		// TODO(raduberinde): we might also need to look at memo.JoinFlags when
 		// choosing a side.
-		leftRowCount := leftExpr.Relational().Stats.RowCount
-		rightRowCount := rightExpr.Relational().Stats.RowCount
+		leftRowCount := leftExpr.Relational().Statistics().RowCount
+		rightRowCount := rightExpr.Relational().Statistics().RowCount
 		if leftRowCount < rightRowCount {
 			if joinType == descpb.LeftSemiJoin {
 				joinType = descpb.RightSemiJoin
@@ -1252,8 +1252,8 @@ func (b *Builder) buildMergeJoin(join *memo.MergeJoinExpr) (execPlan, error) {
 		// it during the costing.
 		// TODO(raduberinde): we might also need to look at memo.JoinFlags when
 		// choosing a side.
-		leftRowCount := leftExpr.Relational().Stats.RowCount
-		rightRowCount := rightExpr.Relational().Stats.RowCount
+		leftRowCount := leftExpr.Relational().Statistics().RowCount
+		rightRowCount := rightExpr.Relational().Statistics().RowCount
 		if leftRowCount < rightRowCount {
 			if joinType == descpb.LeftSemiJoin {
 				joinType = descpb.RightSemiJoin
@@ -2578,7 +2578,7 @@ func (b *Builder) buildWith(with *memo.WithExpr) (execPlan, error) {
 		// to behave like a spoolNode) and using the EXISTS mode.
 		Mode:     exec.SubqueryAllRows,
 		Root:     buffer,
-		RowCount: int64(with.Relational().Stats.RowCountIfAvailable()),
+		RowCount: int64(with.Relational().Statistics().RowCountIfAvailable()),
 	})
 
 	b.addBuiltWithExpr(with.ID, value.outputCols, buffer)
@@ -2632,7 +2632,7 @@ func (b *Builder) buildRecursiveCTE(rec *memo.RecursiveCTEExpr) (execPlan, error
 		if err != nil {
 			return nil, err
 		}
-		rootRowCount := int64(rec.Recursive.Relational().Stats.RowCountIfAvailable())
+		rootRowCount := int64(rec.Recursive.Relational().Statistics().RowCountIfAvailable())
 		return innerBld.factory.ConstructPlan(plan.root, innerBld.subqueries, innerBld.cascades, innerBld.checks, rootRowCount)
 	}
 

pkg/sql/opt/exec/execbuilder/scalar.go

@@ -498,7 +498,7 @@ func (b *Builder) buildArrayFlatten(
 	typ := b.mem.Metadata().ColumnMeta(af.RequestedCol).Type
 	e := b.addSubquery(
 		exec.SubqueryAllRows, typ, root.root, af.OriginalExpr,
-		int64(af.Input.Relational().Stats.RowCountIfAvailable()),
+		int64(af.Input.Relational().Statistics().RowCountIfAvailable()),
 	)
 
 	return tree.NewTypedArrayFlattenExpr(e), nil
@@ -555,7 +555,7 @@ func (b *Builder) buildAny(ctx *buildScalarCtx, scalar opt.ScalarExpr) (tree.Typ
 	typs := types.MakeTuple(contents)
 	subqueryExpr := b.addSubquery(
 		exec.SubqueryAnyRows, typs, plan.root, any.OriginalExpr,
-		int64(any.Input.Relational().Stats.RowCountIfAvailable()),
+		int64(any.Input.Relational().Statistics().RowCountIfAvailable()),
 	)
 
 	// Build the scalar value that is compared against each row.
@@ -591,7 +591,7 @@ func (b *Builder) buildExistsSubquery(
 
 	return b.addSubquery(
 		exec.SubqueryExists, types.Bool, plan.root, exists.OriginalExpr,
-		int64(exists.Input.Relational().Stats.RowCountIfAvailable()),
+		int64(exists.Input.Relational().Statistics().RowCountIfAvailable()),
 	), nil
 }
 
@@ -621,7 +621,7 @@ func (b *Builder) buildSubquery(
 
 	return b.addSubquery(
 		exec.SubqueryOneRow, subquery.Typ, plan.root, subquery.OriginalExpr,
-		int64(input.Relational().Stats.RowCountIfAvailable()),
+		int64(input.Relational().Statistics().RowCountIfAvailable()),
 	), nil
 }
 

pkg/sql/opt/lookupjoin/constraint_builder_test.go

@@ -278,7 +278,8 @@ func makeFilters(
 	}
 
 	// Create a fake Select and input so that normalization rules are run.
-	p := &props.Relational{OutputCols: cols, Cardinality: card, Stats: stats}
+	p := &props.Relational{OutputCols: cols, Cardinality: card}
+	*p.Statistics() = stats
 	fakeRel := f.ConstructFakeRel(&memo.FakeRelPrivate{Props: p})
 	sel := f.ConstructSelect(fakeRel, filters)
 

pkg/sql/opt/memo/expr_format.go

@@ -797,9 +797,9 @@ func (f *ExprFmtCtx) formatRelational(e RelExpr, tp treeprinter.Node) {
 
 	if !f.HasFlags(ExprFmtHideStats) {
 		if f.HasFlags(ExprFmtHideHistograms) {
-			tp.Childf("stats: %s", relational.Stats.StringWithoutHistograms())
+			tp.Childf("stats: %s", relational.Statistics().StringWithoutHistograms())
 		} else {
-			tp.Childf("stats: %s", &relational.Stats)
+			tp.Childf("stats: %s", relational.Statistics())
 		}
 	}
 

pkg/sql/opt/memo/logical_props_builder.go

@@ -938,7 +938,7 @@ func (b *logicalPropsBuilder) buildWithProps(with *WithExpr, rel *props.Relation
 	// Statistics
 	// ----------
 	// Inherited from the input expression.
-	rel.Stats = inputProps.Stats
+	*rel.Statistics() = *inputProps.Statistics()
 }
 
 func (b *logicalPropsBuilder) buildWithScanProps(withScan *WithScanExpr, rel *props.Relational) {
@@ -2134,7 +2134,7 @@ func ensureLookupJoinInputProps(join *LookupJoinExpr, sb *statisticsBuilder) *pr
 		relational.Cardinality = props.AnyCardinality
 		relational.FuncDeps.CopyFrom(MakeTableFuncDep(md, join.Table))
 		relational.FuncDeps.ProjectCols(relational.OutputCols)
-		relational.Stats = *sb.makeTableStatistics(join.Table)
+		*relational.Statistics() = *sb.makeTableStatistics(join.Table)
 	}
 	return relational
 }
@@ -2156,7 +2156,7 @@ func ensureInvertedJoinInputProps(join *InvertedJoinExpr, sb *statisticsBuilder)
 		relational.FuncDeps.ProjectCols(relational.OutputCols)
 
 		// TODO(rytaft): Change this to use inverted index stats once available.
-		relational.Stats = *sb.makeTableStatistics(join.Table)
+		*relational.Statistics() = *sb.makeTableStatistics(join.Table)
 	}
 	return relational
 }
@@ -2201,7 +2201,7 @@ func ensureInputPropsForIndex(
 		relProps.Cardinality = props.AnyCardinality
 		relProps.FuncDeps.CopyFrom(MakeTableFuncDep(md, tabID))
 		relProps.FuncDeps.ProjectCols(relProps.OutputCols)
-		relProps.Stats = *sb.makeTableStatistics(tabID)
+		*relProps.Statistics() = *sb.makeTableStatistics(tabID)
 	}
 }
 
@@ -2624,7 +2624,7 @@ func (b *logicalPropsBuilder) buildMemoCycleTestRelProps(
 	// failures.
 	rel.OutputCols = inputProps.OutputCols
 	// Make the row count non-zero to avoid assertion failures.
-	rel.Stats.RowCount = 1
+	rel.Statistics().RowCount = 1
 }
 
 // WithUses returns the WithUsesMap for the given expression.

pkg/sql/opt/memo/memo.go

@@ -487,7 +487,7 @@ func (m *Memo) Detach() {
 
 		switch t := parent.(type) {
 		case RelExpr:
-			t.Relational().Stats.ColStats = props.ColStatsMap{}
+			t.Relational().Statistics().ColStats = props.ColStatsMap{}
 		}
 	}
 	clearColStats(m.RootExpr())

pkg/sql/opt/memo/memo_test.go

@@ -362,7 +362,7 @@ func TestStatsAvailable(t *testing.T) {
 
 	testNotAvailable := func(expr memo.RelExpr) {
 		traverseExpr(expr, func(e memo.RelExpr) {
-			if e.Relational().Stats.Available {
+			if e.Relational().Statistics().Available {
 				t.Fatal("stats should not be available")
 			}
 		})
@@ -400,7 +400,7 @@ func TestStatsAvailable(t *testing.T) {
 
 	testAvailable := func(expr memo.RelExpr) {
 		traverseExpr(expr, func(e memo.RelExpr) {
-			if !e.Relational().Stats.Available {
+			if !e.Relational().Statistics().Available {
 				t.Fatal("stats should be available")
 			}
 		})