diff --git a/db/backend_test.go b/db/backend_test.go
index 16649cd20..7ead549b0 100644
--- a/db/backend_test.go
+++ b/db/backend_test.go
@@ -3,7 +3,7 @@ package db
 import (
 	"fmt"
 	"os"
-	"path"
+	"path/filepath"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -12,7 +12,7 @@ import (
 )
 
 func cleanupDBDir(dir, name string) {
-	os.RemoveAll(path.Join(dir, name) + ".db")
+	os.RemoveAll(filepath.Join(dir, name) + ".db")
 }
 
 func testBackendGetSetDelete(t *testing.T, backend string) {
@@ -45,15 +45,6 @@ func TestBackendsGetSetDelete(t *testing.T) {
 	}
 }
 
-func assertPanics(t *testing.T, dbType, name string, fn func()) {
-	defer func() {
-		r := recover()
-		assert.NotNil(t, r, cmn.Fmt("expecting %s.%s to panic", dbType, name))
-	}()
-
-	fn()
-}
-
 func TestBackendsNilKeys(t *testing.T) {
 	// test all backends
 	for dbType, creator := range backends {
@@ -62,12 +53,13 @@ func TestBackendsNilKeys(t *testing.T) {
 		defer cleanupDBDir("", name)
 		assert.Nil(t, err)
 
-		assertPanics(t, dbType, "get", func() { db.Get(nil) })
-		assertPanics(t, dbType, "has", func() { db.Has(nil) })
-		assertPanics(t, dbType, "set", func() { db.Set(nil, []byte("abc")) })
-		assertPanics(t, dbType, "setsync", func() { db.SetSync(nil, []byte("abc")) })
-		assertPanics(t, dbType, "delete", func() { db.Delete(nil) })
-		assertPanics(t, dbType, "deletesync", func() { db.DeleteSync(nil) })
+		panicMsg := "expecting %s.%s to panic"
+		assert.Panics(t, func() { db.Get(nil) }, panicMsg, dbType, "get")
+		assert.Panics(t, func() { db.Has(nil) }, panicMsg, dbType, "has")
+		assert.Panics(t, func() { db.Set(nil, []byte("abc")) }, panicMsg, dbType, "set")
+		assert.Panics(t, func() { db.SetSync(nil, []byte("abc")) }, panicMsg, dbType, "setsync")
+		assert.Panics(t, func() { db.Delete(nil) }, panicMsg, dbType, "delete")
+		assert.Panics(t, func() { db.DeleteSync(nil) }, panicMsg, dbType, "deletesync")
 
 		db.Close()
 	}
diff --git a/db/c_level_db.go b/db/c_level_db.go
index 93bc1dfb7..ff8347cc7 100644
--- a/db/c_level_db.go
+++ b/db/c_level_db.go
@@ -4,7 +4,7 @@ package db
 
 import (
 	"fmt"
-	"path"
+	"path/filepath"
 
 	"github.com/jmhodges/levigo"
 )
@@ -27,7 +27,7 @@ type CLevelDB struct {
 }
 
 func NewCLevelDB(name string, dir string) (*CLevelDB, error) {
-	dbPath := path.Join(dir, name+".db")
+	dbPath := filepath.Join(dir, name+".db")
 
 	opts := levigo.NewOptions()
 	opts.SetCache(levigo.NewLRUCache(1 << 30))
diff --git a/db/fsdb.go b/db/fsdb.go
index 8a40d4f19..85adae630 100644
--- a/db/fsdb.go
+++ b/db/fsdb.go
@@ -5,7 +5,6 @@ import (
 	"io/ioutil"
 	"net/url"
 	"os"
-	"path"
 	"path/filepath"
 	"sort"
 	"sync"
@@ -54,7 +53,7 @@ func (db *FSDB) Get(key []byte) []byte {
 	if os.IsNotExist(err) {
 		return nil
 	} else if err != nil {
-		panic(errors.Wrap(err, fmt.Sprintf("Getting key %s (0x%X)", string(key), key)))
+		panic(errors.Wrapf(err, "Getting key %s (0x%X)", string(key), key))
 	}
 	return value
 }
@@ -69,7 +68,7 @@ func (db *FSDB) Has(key []byte) bool {
 	if os.IsNotExist(err) {
 		return false
 	} else if err != nil {
-		panic(errors.Wrap(err, fmt.Sprintf("Getting key %s (0x%X)", string(key), key)))
+		panic(errors.Wrapf(err, "Getting key %s (0x%X)", string(key), key))
 	}
 	return true
 }
@@ -99,7 +98,7 @@ func (db *FSDB) SetNoLock(key []byte, value []byte) {
 	path := db.nameToPath(key)
 	err := write(path, value)
 	if err != nil {
-		panic(errors.Wrap(err, fmt.Sprintf("Setting key %s (0x%X)", string(key), key)))
+		panic(errors.Wrapf(err, "Setting key %s (0x%X)", string(key), key))
 	}
 }
 
@@ -127,7 +126,7 @@ func (db *FSDB) DeleteNoLock(key []byte) {
 	if os.IsNotExist(err) {
 		return
 	} else if err != nil {
-		panic(errors.Wrap(err, fmt.Sprintf("Removing key %s (0x%X)", string(key), key)))
+		panic(errors.Wrapf(err, "Removing key %s (0x%X)", string(key), key))
 	}
 }
 
@@ -172,7 +171,7 @@ func (db *FSDB) Iterator(start, end []byte) Iterator {
 	// Not the best, but probably not a bottleneck depending.
 	keys, err := list(db.dir, start, end)
 	if err != nil {
-		panic(errors.Wrap(err, fmt.Sprintf("Listing keys in %s", db.dir)))
+		panic(errors.Wrapf(err, "Listing keys in %s", db.dir))
 	}
 	sort.Strings(keys)
 	it.keys = keys
@@ -186,7 +185,7 @@ func (db *FSDB) ReverseIterator(start, end []byte) Iterator {
 
 func (db *FSDB) nameToPath(name []byte) string {
 	n := url.PathEscape(string(name))
-	return path.Join(db.dir, n)
+	return filepath.Join(db.dir, n)
 }
 
 // Read some bytes to a file.
diff --git a/db/go_level_db.go b/db/go_level_db.go
index 89015547a..d741c6904 100644
--- a/db/go_level_db.go
+++ b/db/go_level_db.go
@@ -2,7 +2,7 @@ package db
 
 import (
 	"fmt"
-	"path"
+	"path/filepath"
 
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/errors"
@@ -27,7 +27,7 @@ type GoLevelDB struct {
 }
 
 func NewGoLevelDB(name string, dir string) (*GoLevelDB, error) {
-	dbPath := path.Join(dir, name+".db")
+	dbPath := filepath.Join(dir, name+".db")
 	db, err := leveldb.OpenFile(dbPath, nil)
 	if err != nil {
 		return nil, err
@@ -170,13 +170,17 @@ func (mBatch *goLevelDBBatch) Write() {
 // Iterator
 
 func (db *GoLevelDB) Iterator(start, end []byte) Iterator {
-	itr := &goLevelDBIterator{
-		source: db.db.NewIterator(nil, nil),
+	itr := db.db.NewIterator(nil, nil)
+	if len(start) > 0 {
+		itr.Seek(start)
+	} else {
+		itr.First()
+	}
+	return &goLevelDBIterator{
+		source: itr,
 		start:  start,
 		end:    end,
 	}
-	itr.source.Seek(start)
-	return itr
 }
 
 func (db *GoLevelDB) ReverseIterator(start, end []byte) Iterator {