diff --git a/kernel/model/box.go b/kernel/model/box.go
index 1d8df876b..ce1cbc131 100644
--- a/kernel/model/box.go
+++ b/kernel/model/box.go
@@ -495,9 +495,6 @@ func fullReindex() {
 	}
 	treenode.InitBlockTree(true)
 
-	sql.IndexMode()
-	defer sql.NormalMode()
-
 	openedBoxes := Conf.GetOpenedBoxes()
 	for _, openedBox := range openedBoxes {
 		index(openedBox.ID)
diff --git a/kernel/sql/database.go b/kernel/sql/database.go
index 3c8ca4230..d945fa8c0 100644
--- a/kernel/sql/database.go
+++ b/kernel/sql/database.go
@@ -206,34 +206,6 @@ func initHistoryDBTables() {
 	}
 }
 
-func IndexMode() {
-	if nil != db {
-		db.Close()
-	}
-	dsn := util.DBPath + "?_journal_mode=OFF" +
-		"&_synchronous=OFF" +
-		"&_secure_delete=OFF" +
-		"&_cache_size=-20480" +
-		"&_page_size=8192" +
-		"&_busy_timeout=7000" +
-		"&_ignore_check_constraints=ON" +
-		"&_temp_store=MEMORY" +
-		"&_case_sensitive_like=OFF" +
-		"&_locking_mode=EXCLUSIVE"
-	var err error
-	db, err = sql.Open("sqlite3_extended", dsn)
-	if nil != err {
-		logging.LogFatalf("create database failed: %s", err)
-	}
-	db.SetMaxIdleConns(1)
-	db.SetMaxOpenConns(1)
-	db.SetConnMaxLifetime(365 * 24 * time.Hour)
-}
-
-func NormalMode() {
-	initDBConnection()
-}
-
 func initDBConnection() {
 	if nil != db {
 		db.Close()