diff --git a/internal/storage/db.go b/internal/storage/db.go
index d53a765..74bc571 100644
--- a/internal/storage/db.go
+++ b/internal/storage/db.go
@@ -26,6 +26,10 @@ func NewSubPrefixDb(store db.Db, pfx []byte) *SubPrefixDb {
 	}
 }
 
+func(s *SubPrefixDb) SetSession(sessionId string) {
+	s.store.SetSession(sessionId)	
+}
+
 func(s *SubPrefixDb) toKey(k []byte) []byte {
         return append(s.pfx, k...)
 }
diff --git a/internal/storage/timed.go b/internal/storage/timed.go
index 2dce6b2..eedf00c 100644
--- a/internal/storage/timed.go
+++ b/internal/storage/timed.go
@@ -1,6 +1,7 @@
 package storage
 
 import (
+	"bytes"
 	"context"
 	"time"
 	"encoding/binary"
@@ -13,9 +14,10 @@ type TimedDb struct {
 	tdb *SubPrefixDb
 	ttl time.Duration
 	parentPfx uint8
+	parentSession []byte
+	matchPfx map[uint8][][]byte
 }
 
-
 func NewTimedDb(db db.Db, ttl time.Duration) *TimedDb {
 	var b [2]byte
 	binary.BigEndian.PutUint16(b[:], SUBPREFIX_TIME)
@@ -27,11 +29,43 @@ func NewTimedDb(db db.Db, ttl time.Duration) *TimedDb {
 	}
 }
 
+func(tib *TimedDb) WithMatch(pfx uint8, keyPart []byte) *TimedDb {
+	if tib.matchPfx == nil {
+		tib.matchPfx = make(map[uint8][][]byte)
+	}
+	tib.matchPfx[pfx] = append(tib.matchPfx[pfx], keyPart)
+	return tib
+}
+
+func(tib *TimedDb) checkPrefix(pfx uint8, key []byte) bool {
+	var v []byte
+	if tib.matchPfx == nil {
+		return true
+	}
+	for _, v = range(tib.matchPfx[pfx]) {
+		l := len(v)
+		k := append(tib.parentSession, key...)
+		if l > len(k) {
+			continue
+		}
+		logg.Debugf("check the prefix", "v", v, "k", k, "l", l )
+		if bytes.Equal(v, k[:l]) {
+			return true	
+		}
+	}
+	return false
+}
+
 func(tib *TimedDb) SetPrefix(pfx uint8) {
 	tib.Db.SetPrefix(pfx)
 	tib.parentPfx = pfx
 }
 
+func(tib *TimedDb) SetSession(session string) {
+	tib.Db.SetSession(session)
+	tib.parentSession = []byte(session)
+}
+
 func(tib *TimedDb) Put(ctx context.Context, key []byte, val []byte) error {
 	t := time.Now()	
 	b, err := t.MarshalBinary()
@@ -42,13 +76,18 @@ func(tib *TimedDb) Put(ctx context.Context, key []byte, val []byte) error {
 	if err != nil {
 		return err
 	}
-	k := append([]byte{tib.parentPfx}, key...)
 	defer func() {
 		tib.parentPfx = 0
+		tib.parentSession = nil
 	}()
-	err = tib.tdb.Put(ctx, k, b)
-	if err != nil {
-		logg.ErrorCtxf(ctx, "failed to update timestamp of record", err)
+	if tib.checkPrefix(tib.parentPfx, key) {
+		tib.tdb.SetSession("")
+		k := db.ToSessionKey(tib.parentPfx, []byte(tib.parentSession), key)
+		k = append([]byte{tib.parentPfx}, k...)
+		err = tib.tdb.Put(ctx, k, b)
+		if err != nil {
+			logg.ErrorCtxf(ctx, "failed to update timestamp of record", err)
+		}
 	}
 	return nil
 }
@@ -58,11 +97,13 @@ func(tib *TimedDb) Get(ctx context.Context, key []byte) ([]byte, error) {
 	return v, err
 }
 
-func(tib *TimedDb) Stale(ctx context.Context, pfx uint8, key []byte) bool {
-	b := append([]byte{pfx}, key...)
+func(tib *TimedDb) Stale(ctx context.Context, pfx uint8, sessionId string, key []byte) bool {
+	tib.tdb.SetSession("")
+	b := db.ToSessionKey(pfx, []byte(sessionId), key)
+	b = append([]byte{pfx}, b...)
 	v, err := tib.tdb.Get(ctx, b)
 	if err != nil {
-		logg.ErrorCtxf(ctx, "no time entry", "key", key)
+		logg.ErrorCtxf(ctx, "no time entry", "key", key, "b", b)
 		return false
 	}
 	t_now := time.Now()	
diff --git a/internal/storage/timed_test.go b/internal/storage/timed_test.go
index 391d351..38fb63f 100644
--- a/internal/storage/timed_test.go
+++ b/internal/storage/timed_test.go
@@ -25,11 +25,61 @@ func TestStaleDb(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if tdb.Stale(ctx, db.DATATYPE_USERDATA, k) {
+	if tdb.Stale(ctx, db.DATATYPE_USERDATA, "", k) {
 		t.Fatal("expected not stale")
 	}
 	time.Sleep(time.Millisecond)
-	if !tdb.Stale(ctx, db.DATATYPE_USERDATA, k) {
+	if !tdb.Stale(ctx, db.DATATYPE_USERDATA, "", k) {
 		t.Fatal("expected stale")
 	}
 }
+
+func TestFilteredStaleDb(t *testing.T) {
+	ctx := context.Background()
+	mdb := memdb.NewMemDb()
+	err := mdb.Connect(ctx, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	k := []byte("foo")
+	tdb := NewTimedDb(mdb, time.Duration(time.Millisecond))
+	tdb = tdb.WithMatch(db.DATATYPE_STATE, []byte("in"))
+	tdb.SetPrefix(db.DATATYPE_USERDATA)
+	tdb.SetSession("inky")
+	err = tdb.Put(ctx, k, []byte("bar"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	tdb.SetPrefix(db.DATATYPE_STATE)
+	tdb.SetSession("inky")
+	err = tdb.Put(ctx, k, []byte("pinky"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	tdb.SetSession("blinky")
+	err = tdb.Put(ctx, k, []byte("clyde"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if tdb.Stale(ctx, db.DATATYPE_USERDATA, "inky", k) {
+		t.Fatal("expected not stale")
+	}
+	if tdb.Stale(ctx, db.DATATYPE_STATE, "inky", k) {
+		t.Fatal("expected not stale")
+	}
+	if tdb.Stale(ctx, db.DATATYPE_STATE, "blinky", k) {
+		t.Fatal("expected not stale")
+	}
+	time.Sleep(time.Millisecond)
+	if tdb.Stale(ctx, db.DATATYPE_USERDATA, "inky", k) {
+		t.Fatal("expected not stale")
+	}
+	if !tdb.Stale(ctx, db.DATATYPE_STATE, "inky", k) {
+		t.Fatal("expected stale")
+	}
+	if tdb.Stale(ctx, db.DATATYPE_STATE, "blinky", k) {
+		t.Fatal("expected not stale")
+	}
+}