diff --git a/cache/delta.go b/cache/delta.go
index ae3e3c6..7f73c44 100644
--- a/cache/delta.go
+++ b/cache/delta.go
@@ -92,6 +92,7 @@ type DeltaCoordsCache struct {
 	linearImport bool
 	mu           sync.Mutex
 	bunchSize    int64
+	readOnly     bool
 }
 
 func NewDeltaCoordsCache(path string) (*DeltaCoordsCache, error) {
@@ -125,13 +126,21 @@ func (self *DeltaCoordsCache) Close() {
 	self.Cache.Close()
 }
 
+func (self *DeltaCoordsCache) SetReadOnly(val bool) {
+	self.readOnly = val
+}
+
 func (self *DeltaCoordsCache) GetCoord(id int64) (*element.Node, error) {
 	bunchId := self.getBunchId(id)
 	bunch, err := self.getBunch(bunchId)
 	if err != nil {
 		return nil, err
 	}
-	defer bunch.Unlock()
+	if self.readOnly {
+		bunch.Unlock()
+	} else {
+		defer bunch.Unlock()
+	}
 	return bunch.GetCoord(id)
 }
 
diff --git a/goposm.go b/goposm.go
index d82b47e..f565bed 100644
--- a/goposm.go
+++ b/goposm.go
@@ -124,12 +124,6 @@ func main() {
 		}
 	}
 
-	err := osmCache.Open()
-	if err != nil {
-		die(err)
-	}
-	defer osmCache.Close()
-
 	progress := stats.StatsReporter()
 
 	tagmapping, err := mapping.NewMapping(*mappingFile)
@@ -158,12 +152,16 @@ func main() {
 
 	if *read != "" {
 		step := log.StartStep("Reading OSM data")
+		err = osmCache.Open()
+		if err != nil {
+			die(err)
+		}
 		progress.Start()
 		osmCache.Coords.SetLinearImport(true)
 		reader.ReadPbf(osmCache, progress, tagmapping, *read)
 		osmCache.Coords.SetLinearImport(false)
 		progress.Stop()
-		osmCache.Coords.Flush()
+		osmCache.Close()
 		log.StopStep(step)
 	}
 
@@ -192,6 +190,11 @@ func main() {
 			}
 		}
 
+		err = osmCache.Open()
+		if err != nil {
+			die(err)
+		}
+		osmCache.Coords.SetReadOnly(true)
 		pointsTagMatcher := tagmapping.PointMatcher()
 		lineStringsTagMatcher := tagmapping.LineStringMatcher()
 		polygonsTagMatcher := tagmapping.PolygonMatcher()
@@ -204,6 +207,7 @@ func main() {
 
 		// blocks till the Relations.Iter() finishes
 		relWriter.Close()
+		osmCache.Relations.Close()
 
 		ways := osmCache.Ways.Iter()
 		wayWriter := writer.NewWayWriter(osmCache, diffCache, ways, db,
@@ -213,6 +217,7 @@ func main() {
 
 		// blocks till the Ways.Iter() finishes
 		wayWriter.Close()
+		osmCache.Ways.Close()
 
 		nodes := osmCache.Nodes.Iter()
 		nodeWriter := writer.NewNodeWriter(osmCache, nodes, db,
@@ -222,14 +227,15 @@ func main() {
 
 		// blocks till the Nodes.Iter() finishes
 		nodeWriter.Close()
+		osmCache.Nodes.Close()
+		osmCache.Coords.Close()
+		osmCache.Coords.SetReadOnly(false)
 
 		err = db.End()
 		if err != nil {
 			die(err)
 		}
 
-		// insertBuffer.Close()
-		// dbWriter.Close()
 		progress.Stop()
 
 		if *diff {