diff --git a/cmd/influxd/run/server.go b/cmd/influxd/run/server.go
index 74bbe61892..3a3b6b3ab9 100644
--- a/cmd/influxd/run/server.go
+++ b/cmd/influxd/run/server.go
@@ -500,15 +500,25 @@ func (s *Server) reportServer() {
 	dbs := s.MetaClient.Databases()
 	numDatabases := len(dbs)
 
-	numMeasurements := 0
-	numSeries := 0
+	var (
+		numMeasurements int64
+		numSeries       int64
+	)
 
-	// Only needed in the case of a data node
-	if s.TSDBStore != nil {
-		for _, db := range dbs {
-			m, s := s.TSDBStore.MeasurementSeriesCounts(db.Name)
-			numMeasurements += m
-			numSeries += s
+	for _, db := range dbs {
+		name := db.Name
+		n, err := s.TSDBStore.SeriesCardinality(name)
+		if err != nil {
+			s.Logger.Printf("Unable to get series cardinality for database %s: %v", name, err)
+		} else {
+			numSeries += n
+		}
+
+		n, err = s.TSDBStore.MeasurementsCardinality(name)
+		if err != nil {
+			s.Logger.Printf("Unable to get measurement cardinality for database %s: %v", name, err)
+		} else {
+			numMeasurements += n
 		}
 	}
 
diff --git a/services/retention/service.go b/services/retention/service.go
index 41bffb56c2..03efdf8fa7 100644
--- a/services/retention/service.go
+++ b/services/retention/service.go
@@ -18,7 +18,6 @@ type Service struct {
 		PruneShardGroups() error
 	}
 	TSDBStore interface {
-		ShardIDs() []uint64
 		DeleteShard(shardID uint64) error
 	}
 
@@ -119,16 +118,14 @@ func (s *Service) deleteShards() {
 				}
 			}
 
-			for _, id := range s.TSDBStore.ShardIDs() {
-				if di, ok := deletedShardIDs[id]; ok {
-					if err := s.TSDBStore.DeleteShard(id); err != nil {
-						s.logger.Info(fmt.Sprintf("failed to delete shard ID %d from database %s, retention policy %s: %s",
-							id, di.db, di.rp, err.Error()))
-						continue
-					}
-					s.logger.Info(fmt.Sprintf("shard ID %d from database %s, retention policy %s, deleted",
-						id, di.db, di.rp))
+			for id, info := range deletedShardIDs {
+				if err := s.TSDBStore.DeleteShard(id); err != nil {
+					s.logger.Printf("failed to delete shard ID %d from database %s, retention policy %s: %s",
+						id, info.db, info.rp, err.Error())
+					continue
 				}
+				s.logger.Printf("shard ID %d from database %s, retention policy %s, deleted",
+					id, info.db, info.rp)
 			}
 			if err := s.MetaClient.PruneShardGroups(); err != nil {
 				s.logger.Info(fmt.Sprintf("error pruning shard groups: %s", err))
diff --git a/tsdb/engine.go b/tsdb/engine.go
index c37a51763f..2833cd2b00 100644
--- a/tsdb/engine.go
+++ b/tsdb/engine.go
@@ -28,10 +28,12 @@ var (
 type Engine interface {
 	Open() error
 	Close() error
-
+	SetEnabled(enabled bool)
 	WithLogger(zap.Logger)
+
 	LoadMetadataIndex(shardID uint64, index *DatabaseIndex) error
 
+	CreateSnapshot() (string, error)
 	Backup(w io.Writer, basePath string, since time.Time) error
 	Restore(r io.Reader, basePath string) error
 
@@ -39,25 +41,18 @@ type Engine interface {
 	WritePoints(points []models.Point) error
 
 	CreateSeries(measurment string, series *Series) (*Series, error)
-	Series(key string) (*Series, error)
-	ContainsSeries(keys []string) (map[string]bool, error)
-	DeleteSeries(keys []string) error
 	DeleteSeriesRange(keys []string, min, max int64) error
-	SeriesCount() (n int, err error)
+	Series(key string) (*Series, error)
+	SeriesCardinality() (n int64, err error)
 
 	CreateMeasurement(name string) (*Measurement, error)
+	DeleteMeasurement(name string, seriesKeys []string) error
 	Measurement(name string) (*Measurement, error)
 	Measurements() (Measurements, error)
+	MeasurementCardinality() (n int64, err error)
 	MeasurementsByExpr(expr influxql.Expr) (Measurements, bool, error)
 	MeasurementsByRegex(re *regexp.Regexp) (Measurements, error)
 	MeasurementFields(measurement string) *MeasurementFields
-	DeleteMeasurement(name string, seriesKeys []string) error
-
-	CreateSnapshot() (string, error)
-	SetEnabled(enabled bool)
-
-	// Format will return the format for the engine
-	Format() EngineFormat
 
 	// Statistics will return statistics relevant to this engine.
 	Statistics(tags map[string]string) []models.Statistic
diff --git a/tsdb/engine/tsm1/engine.go b/tsdb/engine/tsm1/engine.go
index efcac07ae4..d61dd49ab5 100644
--- a/tsdb/engine/tsm1/engine.go
+++ b/tsdb/engine/tsm1/engine.go
@@ -282,13 +282,6 @@ func (e *Engine) disableSnapshotCompactions() {
 // Path returns the path the engine was opened with.
 func (e *Engine) Path() string { return e.path }
 
-// Index returns the database index.
-func (e *Engine) Index() *tsdb.DatabaseIndex {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-	return e.index
-}
-
 func (e *Engine) Measurement(name string) (*tsdb.Measurement, error) {
 	return e.index.Measurement(name), nil
 }
@@ -297,6 +290,10 @@ func (e *Engine) Measurements() (tsdb.Measurements, error) {
 	return e.index.Measurements(), nil
 }
 
+func (e *Engine) MeasurementCardinality() (int64, error) {
+	panic("TODO: edd")
+}
+
 func (e *Engine) MeasurementsByExpr(expr influxql.Expr) (tsdb.Measurements, bool, error) {
 	return e.index.MeasurementsByExpr(expr)
 }
@@ -325,9 +322,8 @@ func (e *Engine) MeasurementFields(measurement string) *tsdb.MeasurementFields {
 	return m
 }
 
-// Format returns the format type of this engine.
-func (e *Engine) Format() tsdb.EngineFormat {
-	return tsdb.TSM1Format
+func (e *Engine) SeriesCardinality() (int64, error) {
+	panic("TODO: edd")
 }
 
 // EngineStatistics maintains statistics for the engine.
@@ -735,9 +731,9 @@ func (e *Engine) WritePoints(points []models.Point) error {
 	return err
 }
 
-// ContainsSeries returns a map of keys indicating whether the key exists and
+// containsSeries returns a map of keys indicating whether the key exists and
 // has values or not.
-func (e *Engine) ContainsSeries(keys []string) (map[string]bool, error) {
+func (e *Engine) containsSeries(keys []string) (map[string]bool, error) {
 	// keyMap is used to see if a given key exists.  keys
 	// are the measurement + tagset (minus separate & field)
 	keyMap := map[string]bool{}
@@ -763,8 +759,8 @@ func (e *Engine) ContainsSeries(keys []string) (map[string]bool, error) {
 	return keyMap, nil
 }
 
-// DeleteSeries removes all series keys from the engine.
-func (e *Engine) DeleteSeries(seriesKeys []string) error {
+// deleteSeries removes all series keys from the engine.
+func (e *Engine) deleteSeries(seriesKeys []string) error {
 	return e.DeleteSeriesRange(seriesKeys, math.MinInt64, math.MaxInt64)
 }
 
@@ -837,7 +833,7 @@ func (e *Engine) DeleteSeriesRange(seriesKeys []string, min, max int64) error {
 
 	// Have we deleted all points for the series? If so, we need to remove
 	// the series from the index.
-	existing, err := e.ContainsSeries(seriesKeys)
+	existing, err := e.containsSeries(seriesKeys)
 	if err != nil {
 		return err
 	}
@@ -864,7 +860,7 @@ func (e *Engine) DeleteMeasurement(name string, seriesKeys []string) error {
 	delete(e.measurementFields, name)
 	e.fieldsMu.Unlock()
 
-	if err := e.DeleteSeries(seriesKeys); err != nil {
+	if err := e.deleteSeries(seriesKeys); err != nil {
 		return err
 	}
 
@@ -873,23 +869,6 @@ func (e *Engine) DeleteMeasurement(name string, seriesKeys []string) error {
 	return nil
 }
 
-// SeriesCount returns the number of series buckets on the shard.
-func (e *Engine) SeriesCount() (n int, err error) {
-	return e.index.SeriesN(), nil
-}
-
-// LastModified returns the time when this shard was last modified.
-func (e *Engine) LastModified() time.Time {
-	walTime := e.WAL.LastWriteTime()
-	fsTime := e.FileStore.LastModified()
-
-	if walTime.After(fsTime) {
-		return walTime
-	}
-
-	return fsTime
-}
-
 func (e *Engine) CreateSeries(measurment string, series *tsdb.Series) (*tsdb.Series, error) {
 	return e.index.CreateSeriesIndexIfNotExists(measurment, series), nil
 }
diff --git a/tsdb/engine/tsm1/engine_test.go b/tsdb/engine/tsm1/engine_test.go
index f571be9973..d2cc08b3f4 100644
--- a/tsdb/engine/tsm1/engine_test.go
+++ b/tsdb/engine/tsm1/engine_test.go
@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"fmt"
 	"io/ioutil"
+	"math"
 	"math/rand"
 	"os"
 	"path/filepath"
@@ -113,7 +114,7 @@ func TestEngine_DeleteWALLoadMetadata(t *testing.T) {
 	}
 
 	// Remove series.
-	if err := e.DeleteSeries([]string{"cpu,host=A"}); err != nil {
+	if err := e.DeleteSeriesRange([]string{"cpu,host=A"}, math.MinInt64, math.MaxInt64); err != nil {
 		t.Fatalf("failed to delete series: %s", err.Error())
 	}
 
@@ -221,11 +222,9 @@ func TestEngine_CreateIterator_Cache_Ascending(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A value=1.2 2000000000`,
@@ -276,11 +275,9 @@ func TestEngine_CreateIterator_Cache_Descending(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A value=1.2 2000000000`,
@@ -331,11 +328,9 @@ func TestEngine_CreateIterator_TSM_Ascending(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A value=1.2 2000000000`,
@@ -387,11 +382,9 @@ func TestEngine_CreateIterator_TSM_Descending(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A value=1.2 2000000000`,
@@ -443,12 +436,10 @@ func TestEngine_CreateIterator_Aux(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("F", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A F=100 1000000000`,
@@ -502,15 +493,14 @@ func TestEngine_CreateIterator_Condition(t *testing.T) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
-	e.Index().Measurement("cpu").SetFieldName("X")
-	e.Index().Measurement("cpu").SetFieldName("Y")
+	e.CreateMeasurement("cpu")
+	e.MustMeasurement("cpu").SetFieldName("X")
+	e.MustMeasurement("cpu").SetFieldName("Y")
+
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("X", influxql.Float, false)
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("Y", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
-
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 	if err := e.WritePointsString(
 		`cpu,host=A value=1.1 1000000000`,
 		`cpu,host=A X=10 1000000000`,
@@ -595,7 +585,7 @@ func TestEngine_DeleteSeries(t *testing.T) {
 		t.Fatalf("series count mismatch: exp %v, got %v", exp, got)
 	}
 
-	if err := e.DeleteSeries([]string{"cpu,host=A"}); err != nil {
+	if err := e.DeleteSeriesRange([]string{"cpu,host=A"}, math.MinInt64, math.MaxInt64); err != nil {
 		t.Fatalf("failed to delete series: %v", err)
 	}
 
@@ -760,7 +750,7 @@ func benchmarkEngine_WritePoints(b *testing.B, batchSize int) {
 	e := MustOpenEngine()
 	defer e.Close()
 
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
 
 	pp := make([]models.Point, 0, batchSize)
@@ -902,10 +892,9 @@ func MustInitBenchmarkEngine(pointN int) *Engine {
 	e := MustOpenEngine()
 
 	// Initialize metadata.
-	e.Index().CreateMeasurementIndexIfNotExists("cpu")
+	e.CreateMeasurement("cpu")
 	e.MeasurementFields("cpu").CreateFieldIfNotExists("value", influxql.Float, false)
-	si := e.Index().CreateSeriesIndexIfNotExists("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
-	si.AssignShard(1)
+	e.CreateSeries("cpu", tsdb.NewSeries("cpu,host=A", models.NewTags(map[string]string{"host": "A"})))
 
 	// Generate time ascending points with jitterred time & value.
 	rand := rand.New(rand.NewSource(0))
@@ -1004,6 +993,16 @@ func (e *Engine) MustWriteSnapshot() {
 	}
 }
 
+// MustMeasurement calls Measurement on the underlying tsdb.Engine, and panics
+// if it returns an error.
+func (e *Engine) MustMeasurement(name string) *tsdb.Measurement {
+	m, err := e.Engine.Measurement(name)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
 // WritePointsString parses a string buffer and writes the points.
 func (e *Engine) WritePointsString(buf ...string) error {
 	return e.WritePoints(MustParsePointsString(strings.Join(buf, "\n")))
diff --git a/tsdb/shard.go b/tsdb/shard.go
index fb087ac880..19141e3b53 100644
--- a/tsdb/shard.go
+++ b/tsdb/shard.go
@@ -5,6 +5,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
+	"math"
 	"os"
 	"path/filepath"
 	"sort"
@@ -127,8 +129,9 @@ type Shard struct {
 
 // NewShard returns a new initialized Shard.
 func NewShard(id uint64, path string, walPath string, options EngineOptions) *Shard {
-	db, rp := DecodeStorePath(path)
+	db, rp := decodeStorePath(path)
 	logger := zap.New(zap.NullEncoder())
+
 	s := &Shard{
 		id:      id,
 		path:    path,
@@ -198,7 +201,7 @@ func (s *Shard) Statistics(tags map[string]string) []models.Statistic {
 		return nil
 	}
 
-	seriesN, _ := s.engine.SeriesCount()
+	seriesN, _ := s.engine.SeriesCardinality()
 	tags = s.defaultTags.Merge(tags)
 	statistics := []models.Statistic{{
 		Name: "shard",
@@ -261,7 +264,7 @@ func (s *Shard) Open() error {
 
 		s.engine = e
 
-		count, err := s.engine.SeriesCount()
+		count, err := s.engine.SeriesCardinality()
 		if err != nil {
 			return err
 		}
@@ -418,26 +421,9 @@ func (s *Shard) WritePoints(points []models.Point) error {
 	return writeError
 }
 
-// ContainsSeries determines if the shard contains the provided series keys. The
-// returned map contains all the provided keys that are in the shard, and the
-// value for each key will be true if the shard has values for that key.
-func (s *Shard) ContainsSeries(seriesKeys []string) (map[string]bool, error) {
-	if err := s.ready(); err != nil {
-		return nil, err
-	}
-
-	return s.engine.ContainsSeries(seriesKeys)
-}
-
 // DeleteSeries deletes a list of series.
 func (s *Shard) DeleteSeries(seriesKeys []string) error {
-	if err := s.ready(); err != nil {
-		return err
-	}
-	if err := s.engine.DeleteSeries(seriesKeys); err != nil {
-		return err
-	}
-	return nil
+	return s.DeleteSeriesRange(seriesKeys, math.MinInt64, math.MaxInt64)
 }
 
 // DeleteSeriesRange deletes all values from seriesKeys with timestamps between min and max (inclusive).
@@ -585,7 +571,7 @@ func (s *Shard) validateSeriesAndFields(points []models.Point) ([]models.Point,
 				return nil, nil, err
 			}
 
-			if s.options.Config.MaxSeriesPerDatabase > 0 && cnt+1 > s.options.Config.MaxSeriesPerDatabase {
+			if s.options.Config.MaxSeriesPerDatabase > 0 && cnt+1 > int64(s.options.Config.MaxSeriesPerDatabase) {
 				atomic.AddInt64(&s.stats.WritePointsDropped, 1)
 				dropped++
 				reason = fmt.Sprintf("db %s max series limit reached: (%d/%d)", s.database, cnt, s.options.Config.MaxSeriesPerDatabase)
@@ -681,12 +667,12 @@ func (s *Shard) MeasurementsByExpr(cond influxql.Expr) (Measurements, bool, erro
 	return s.engine.MeasurementsByExpr(cond)
 }
 
-// SeriesCount returns the number of series buckets on the shard.
-func (s *Shard) SeriesCount() (int, error) {
+// SeriesCardinality returns the number of series buckets on the shard.
+func (s *Shard) SeriesCardinality() (int64, error) {
 	if err := s.ready(); err != nil {
 		return 0, err
 	}
-	return s.engine.SeriesCount()
+	return s.engine.SeriesCardinality()
 }
 
 // Series returns a series by key.
diff --git a/tsdb/shard_test.go b/tsdb/shard_test.go
index 7ec41742a5..d75a86e733 100644
--- a/tsdb/shard_test.go
+++ b/tsdb/shard_test.go
@@ -65,12 +65,12 @@ func TestShardWriteAndIndex(t *testing.T) {
 	}
 
 	validateIndex := func() {
-		cnt, err := sh.SeriesCount()
+		cnt, err := sh.SeriesCardinality()
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		if got, exp := cnt, 1; got != exp {
+		if got, exp := cnt, int64(1); got != exp {
 			t.Fatalf("got %v series, exp %v series in index", got, exp)
 		}
 
@@ -346,11 +346,11 @@ func TestShardWriteAddNewField(t *testing.T) {
 		t.Fatalf(err.Error())
 	}
 
-	cnt, err := sh.SeriesCount()
+	cnt, err := sh.SeriesCardinality()
 	if err != nil {
 		t.Fatal(err)
 	}
-	if got, exp := cnt, 1; got != exp {
+	if got, exp := cnt, int64(1); got != exp {
 		t.Fatalf("got %d series, exp %d series in index", got, exp)
 	}
 
@@ -470,11 +470,11 @@ func TestShard_Close_RemoveIndex(t *testing.T) {
 		t.Fatalf(err.Error())
 	}
 
-	cnt, err := sh.SeriesCount()
+	cnt, err := sh.SeriesCardinality()
 	if err != nil {
 		t.Fatal(err)
 	}
-	if got, exp := cnt, 1; got != exp {
+	if got, exp := cnt, int64(1); got != exp {
 		t.Fatalf("got %d series, exp %d series in index", got, exp)
 	}
 
@@ -482,10 +482,10 @@ func TestShard_Close_RemoveIndex(t *testing.T) {
 	sh.Close()
 	sh.Open()
 
-	if cnt, err = sh.SeriesCount(); err != nil {
+	if cnt, err = sh.SeriesCardinality(); err != nil {
 		t.Fatal(err)
 	}
-	if got, exp := cnt, 1; got != exp {
+	if got, exp := cnt, int64(1); got != exp {
 		t.Fatalf("got %d series, exp %d series in index", got, exp)
 	}
 
diff --git a/tsdb/store.go b/tsdb/store.go
index e1162b45f7..9de5022015 100644
--- a/tsdb/store.go
+++ b/tsdb/store.go
@@ -450,9 +450,16 @@ func (s *Store) DeleteMeasurement(database, name string) error {
 }
 
 // filterShards returns a slice of shards where fn returns true
-// for the shard.
+// for the shard. If the provided predicate is nil then all shards are returned.
 func (s *Store) filterShards(fn func(sh *Shard) bool) []*Shard {
-	shards := make([]*Shard, 0, len(s.shards))
+	var shards []*Shard
+	if fn == nil {
+		shards = make([]*Shard, 0, len(s.shards))
+		fn = func(*Shard) bool { return true }
+	} else {
+		shards = make([]*Shard, 0)
+	}
+
 	for _, sh := range s.shards {
 		if fn(sh) {
 			shards = append(shards, sh)
@@ -504,21 +511,6 @@ func (s *Store) walkShards(shards []*Shard, fn func(sh *Shard) error) error {
 	return err
 }
 
-// ShardIDs returns a slice of all ShardIDs under management, in arbitrary order.
-func (s *Store) ShardIDs() []uint64 {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	return s.shardIDs()
-}
-
-func (s *Store) shardIDs() []uint64 {
-	a := make([]uint64, 0, len(s.shards))
-	for shardID := range s.shards {
-		a = append(a, shardID)
-	}
-	return a
-}
-
 // shardsSlice returns an ordered list of shards.
 func (s *Store) shardsSlice() []*Shard {
 	a := make([]*Shard, 0, len(s.shards))
@@ -544,12 +536,14 @@ func (s *Store) Databases() []string {
 // DiskSize returns the size of all the shard files in bytes.
 // This size does not include the WAL size.
 func (s *Store) DiskSize() (int64, error) {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
 	var size int64
-	for _, shardID := range s.ShardIDs() {
-		shard := s.Shard(shardID)
-		sz, err := shard.DiskSize()
+
+	s.mu.RLock()
+	allShards := s.filterShards(nil)
+	s.mu.RUnlock()
+
+	for _, sh := range allShards {
+		sz, err := sh.DiskSize()
 		if err != nil {
 			return 0, err
 		}
@@ -558,6 +552,17 @@ func (s *Store) DiskSize() (int64, error) {
 	return size, nil
 }
 
+// SeriesCardinality returns the series cardinality for the provided database.
+func (s *Store) SeriesCardinality(database string) (int64, error) {
+	panic("TODO: edd")
+}
+
+// MeasurementsCardinality returns the measurement cardinality for the provided
+// database.
+func (s *Store) MeasurementsCardinality(database string) (int64, error) {
+	panic("TODO: edd")
+}
+
 // BackupShard will get the shard and have the engine backup since the passed in
 // time to the writer.
 func (s *Store) BackupShard(id uint64, since time.Time, w io.Writer) error {
@@ -669,14 +674,6 @@ func (s *Store) DeleteSeries(database string, sources []influxql.Source, conditi
 	}
 
 	// delete the raw series data.
-	return s.deleteSeries(database, seriesKeys, min, max)
-}
-
-func (s *Store) deleteSeries(database string, seriesKeys []string, min, max int64) error {
-	s.mu.RLock()
-	shards := s.filterShards(byDatabase(database))
-	s.mu.RUnlock()
-
 	return s.walkShards(shards, func(sh *Shard) error {
 		if err := sh.DeleteSeriesRange(seriesKeys, min, max); err != nil {
 			return err
@@ -953,9 +950,9 @@ func (e *Store) filterShowSeriesResult(limit, offset int, rows models.Rows) mode
 	return filteredSeries
 }
 
-// DecodeStorePath extracts the database and retention policy names
+// decodeStorePath extracts the database and retention policy names
 // from a given shard or WAL path.
-func DecodeStorePath(shardOrWALPath string) (database, retentionPolicy string) {
+func decodeStorePath(shardOrWALPath string) (database, retentionPolicy string) {
 	// shardOrWALPath format: /maybe/absolute/base/then/:database/:retentionPolicy/:nameOfShardOrWAL
 
 	// Discard the last part of the path (the shard name or the wal name).