diff --git a/src/backup/sync.js b/src/backup/sync.js
index 78922c4..a6d7476 100644
--- a/src/backup/sync.js
+++ b/src/backup/sync.js
@@ -80,6 +80,7 @@ const queueSync = {
                     console.warn(`Queue-Sync: queue list is empty, but hash list is not empty for ${node_i}`);
                 //all blocks synced, remove the sync instance
                 console.info(`END: Data sync for ${node_i}`);
+                clearInterval(r.check_interval);
                 delete this.list[node_i];
                 //indicate next node for ordering
                 _nextNode.send(packet_.construct({
diff --git a/src/database.js b/src/database.js
index 613741f..63c8f3f 100644
--- a/src/database.js
+++ b/src/database.js
@@ -476,12 +476,11 @@ DB.clearAuthorisedAppData = function (snID, app, adminID, subAdmins, timestamp)
 
 DB.clearUnauthorisedAppData = function (snID, appList, timestamp) {
     return new Promise((resolve, reject) => {
-        let statement = "SELECT * FROM _" + snID +
+        let statement = "DELETE FROM _" + snID +
             " WHERE " + H_struct.TIME + "<?" +
             (appList.length ? " AND " +
                 H_struct.APPLICATION + " NOT IN (" + appList.map(a => "?").join(", ") + ")" :
                 "");
-        console.debug(statement, [timestamp].concat(appList))
         queryResolve(statement, [timestamp].concat(appList))
             .then(result => resolve(result))
             .catch(error => reject(error));