diff --git a/block.go b/block.go
index 67cd57491..232e64e67 100644
--- a/block.go
+++ b/block.go
@@ -64,11 +64,6 @@ type Appendable interface {
 	Appender() Appender
 }
 
-// Queryable defines an entity which provides a Querier.
-type Queryable interface {
-	Querier(mint, maxt int64) Querier
-}
-
 // BlockMeta provides meta information about a block.
 type BlockMeta struct {
 	// Unique identifier for the block and its contents. Changes on compaction.
diff --git a/db.go b/db.go
index c9745cfc6..87b5ed253 100644
--- a/db.go
+++ b/db.go
@@ -165,8 +165,7 @@ func Open(dir string, l log.Logger, r prometheus.Registerer, opts *Options) (db
 		return nil, err
 	}
 	if l == nil {
-		l = log.NewLogfmtLogger(os.Stdout)
-		l = log.With(l, "ts", log.DefaultTimestampUTC, "caller", log.DefaultCaller)
+		l = log.NewNopLogger()
 	}
 	if opts == nil {
 		opts = DefaultOptions
diff --git a/index.go b/index.go
index fd9b25162..3cdaad74d 100644
--- a/index.go
+++ b/index.go
@@ -570,6 +570,9 @@ var (
 	errInvalidFlag = fmt.Errorf("invalid flag")
 )
 
+// NewIndexReader returns a new IndexReader on the given directory.
+func NewIndexReader(dir string) (IndexReader, error) { return newIndexReader(dir) }
+
 // newIndexReader returns a new indexReader on the given directory.
 func newIndexReader(dir string) (*indexReader, error) {
 	f, err := openMmapFile(filepath.Join(dir, "index"))