reverse keyless indexscans apply reversal (#8541)

dolthub · Nov 14, 2024 · 0e34d26 · 0e34d26
1 parent ead97bf
commit 0e34d26
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Showing 2 changed files with 12 additions and 14 deletions.
diff --git a/go/libraries/doltcore/sqle/index/index_reader.go b/go/libraries/doltcore/sqle/index/index_reader.go
@@ -57,7 +57,7 @@ func RowIterForIndexLookup(ctx *sql.Context, t DoltTableable, lookup sql.IndexLo
 		if err != nil {
 			return nil, err
 		}
-		return RowIterForProllyRange(ctx, idx, prollyRanges[0], pkSch, columns, durableState)
+		return RowIterForProllyRange(ctx, idx, prollyRanges[0], pkSch, columns, durableState, lookup.IsReverse)
 	} else {
 		nomsRanges, err := idx.nomsRanges(ctx, mysqlRanges...)
 		if err != nil {
@@ -67,15 +67,15 @@ func RowIterForIndexLookup(ctx *sql.Context, t DoltTableable, lookup sql.IndexLo
 	}
 }
 
-func RowIterForProllyRange(ctx *sql.Context, idx DoltIndex, r prolly.Range, pkSch sql.PrimaryKeySchema, projections []uint64, durableState *durableIndexState) (sql.RowIter, error) {
+func RowIterForProllyRange(ctx *sql.Context, idx DoltIndex, r prolly.Range, pkSch sql.PrimaryKeySchema, projections []uint64, durableState *durableIndexState, reverse bool) (sql.RowIter, error) {
 	if projections == nil {
 		projections = idx.Schema().GetAllCols().Tags
 	}
 
 	if sql.IsKeyless(pkSch.Schema) {
 		// in order to resolve row cardinality, keyless indexes must always perform
 		// an indirect lookup through the clustered index.
-		return newProllyKeylessIndexIter(ctx, idx, r, nil, pkSch, projections, durableState.Primary, durableState.Secondary)
+		return newProllyKeylessIndexIter(ctx, idx, r, nil, pkSch, projections, durableState.Primary, durableState.Secondary, reverse)
 	}
 
 	covers := idx.coversColumns(durableState, projections)
@@ -697,15 +697,17 @@ func (i *keylessMapIter) Next(ctx context.Context) (val.Tuple, val.Tuple, error)
 func (ib *keylessIndexImplBuilder) NewPartitionRowIter(ctx *sql.Context, part sql.Partition) (sql.RowIter, error) {
 	var prollyRange prolly.Range
 	var doltgresRange *DoltgresRange
+	var reverse bool
 	switch p := part.(type) {
 	case rangePartition:
 		prollyRange = p.prollyRange
+		reverse = p.isReverse
 	case pointPartition:
 		prollyRange = p.r
 	case DoltgresPartition:
 		doltgresRange = &p.rang
 	}
-	return newProllyKeylessIndexIter(ctx, ib.idx, prollyRange, doltgresRange, ib.sch, ib.projections, ib.s.Primary, ib.s.Secondary)
+	return newProllyKeylessIndexIter(ctx, ib.idx, prollyRange, doltgresRange, ib.sch, ib.projections, ib.s.Primary, ib.s.Secondary, reverse)
 }
 
 func (ib *keylessIndexImplBuilder) NewSecondaryIter(strict bool, cnt int, nullSafe []bool) SecondaryLookupIterGen {

diff --git a/go/libraries/doltcore/sqle/index/prolly_index_iter.go b/go/libraries/doltcore/sqle/index/prolly_index_iter.go
@@ -292,20 +292,16 @@ type prollyKeylessIndexIter struct {
 
 var _ sql.RowIter = prollyKeylessIndexIter{}
 
-func newProllyKeylessIndexIter(
-	ctx *sql.Context,
-	idx DoltIndex,
-	rng prolly.Range,
-	doltgresRange *DoltgresRange,
-	pkSch sql.PrimaryKeySchema,
-	projections []uint64,
-	rows, dsecondary durable.Index,
-) (prollyKeylessIndexIter, error) {
+func newProllyKeylessIndexIter(ctx *sql.Context, idx DoltIndex, rng prolly.Range, doltgresRange *DoltgresRange, pkSch sql.PrimaryKeySchema, projections []uint64, rows, dsecondary durable.Index, reverse bool) (prollyKeylessIndexIter, error) {
 	secondary := durable.ProllyMapFromIndex(dsecondary)
 	var indexIter prolly.MapIter
 	var err error
 	if doltgresRange == nil {
-		indexIter, err = secondary.IterRange(ctx, rng)
+		if reverse {
+			indexIter, err = secondary.IterRangeReverse(ctx, rng)
+		} else {
+			indexIter, err = secondary.IterRange(ctx, rng)
+		}
 		if err != nil {
 			return prollyKeylessIndexIter{}, err
 		}