Generate index lookups for filters that appear in lateral joins

sql/analyzer/apply_indexes_from_outer_scope.go

@@ -29,10 +29,6 @@ import (
 // apply, effectively, an indexed join between two tables, one of which is defined in the outer scope. This is similar
 // to the process in the join analyzer.
 func applyIndexesFromOuterScope(ctx *sql.Context, a *Analyzer, n sql.Node, scope *plan.Scope, sel RuleSelector, qFlags *sql.QueryFlags) (sql.Node, transform.TreeIdentity, error) {
-	if scope.IsEmpty() {
-		return n, transform.SameTree, nil
-	}
-
 	// this isn't good enough: we need to consider aliases defined in the outer scope as well for this analysis
 	tableAliases, err := getTableAliases(n, scope)
 	if err != nil {
@@ -281,6 +277,11 @@ func tablesInScope(scope *plan.Scope) []string {
 			tables[col.Source] = true
 		}
 	}
+	for _, table := range scope.JoinSiblings() {
+		for name, _ := range getTablesByName(table) {
+			tables[name] = true
+		}
+	}
 	var tableSlice []string
 	for table := range tables {
 		tableSlice = append(tableSlice, table)

sql/plan/scope.go

@@ -340,9 +340,15 @@ func (s *Scope) InInsertSource() bool {
 }
 
 func (s *Scope) JoinSiblings() []sql.Node {
+	if s == nil {
+		return nil
+	}
 	return s.joinSiblings
 }
 
 func (s *Scope) Correlated() sql.ColSet {
+	if s == nil {
+		return sql.ColSet{}
+	}
 	return s.corr
 }