perf: do not match each token in aggregation

frac/active_index.go

@@ -244,6 +244,10 @@ func (si *activeTokenIndex) GetValByTID(tid uint32, field string) []byte {
 	return si.tokenList.GetValByTID(tid, field)
 }
 
+func (si *activeTokenIndex) GetTIDsByField(field string) ([]uint32, error) {
+	return si.tokenList.GetTIDsByField(field), nil
+}
+
 func (si *activeTokenIndex) GetTIDsByTokenExpr(t parser.Token) ([]uint32, error) {
 	return si.tokenList.FindPattern(si.ctx, t)
 }

frac/processor/eval_tree.go

@@ -200,11 +200,13 @@ func iteratorFromLiteral(
 	iteratorLimit iteratorLimit,
 	order seq.DocsOrder,
 ) (*SourcedNodeIterator, error) {
-	m := sw.Start("get_tids_by_token_expr")
-	tids, err := ti.GetTIDsByTokenExpr(literal)
+	m := sw.Start("get_tids_by_field")
+	// For aggregations we can receive the first and the last TID for field,
+	// because we build tree over *all* token values.
+	tids, err := ti.GetTIDsByField(literal.Field)
 	m.Stop()
 	if err != nil {
-		return nil, fmt.Errorf("getting TIDs by token expression: %s", err)
+		return nil, fmt.Errorf("getting TIDs for field %q: %s", literal.Field, err)
 	}
 
 	if len(tids) > maxTIDs && maxTIDs > 0 {

frac/processor/search.go

@@ -33,6 +33,7 @@ type idsIndex interface {
 
 type tokenIndex interface {
 	GetValByTID(tid uint32, field string) []byte
+	GetTIDsByField(field string) ([]uint32, error)
 	GetTIDsByTokenExpr(token parser.Token) ([]uint32, error)
 	GetLIDsFromTIDs(tids []uint32, stats lids.Counter, minLID, maxLID uint32, order seq.DocsOrder) []node.Node
 }

frac/sealed_index.go

@@ -237,6 +237,25 @@ func (ti *sealedTokenIndex) GetValByTID(tid uint32, field string) []byte {
 	return nil
 }
 
+func (ti *sealedTokenIndex) GetTIDsByField(field string) ([]uint32, error) {
+	table := ti.tokenTableLoader.Load()
+
+	entries := table.SelectEntries(field, "")
+	if len(entries) == 0 {
+		return nil, nil
+	}
+
+	first := entries[0].StartTID
+	last := entries[len(entries)-1].GetLastTID()
+
+	tids := make([]uint32, (last-first)+1)
+	for i := range tids {
+		tids[i] = first + uint32(i)
+	}
+
+	return tids, nil
+}
+
 func (ti *sealedTokenIndex) GetTIDsByTokenExpr(t parser.Token) ([]uint32, error) {
 	field := parser.GetField(t)
 	searchStr := parser.GetHint(t)