diff --git a/EdgeManager/EDataCapture/ENodeConfigure.php b/EdgeManager/EDataCapture/ENodeConfigure.php
index ba6de1f..687d7d6 100644
--- a/EdgeManager/EDataCapture/ENodeConfigure.php
+++ b/EdgeManager/EDataCapture/ENodeConfigure.php
@@ -9,6 +9,7 @@ class ENodeConfigure {
     ) {}
 
     function add_node() {
+        pg_query($this -> dbconn, "BEGIN");
         $exists = pg_query($this -> dbconn, sprintf(
             "SELECT EXISTS(
                 SELECT 1 FROM hf_mes_scada_data_capture_node_configure
@@ -16,12 +17,13 @@ class ENodeConfigure {
                 AND working_subclass = '%s'
             )", $this -> post -> code, $this -> post -> working_subclass
         ));
-        if (pg_fetch_assoc($exists)['exists'] == 't') {
+        if (pg_fetch_assoc($exists)['exists'] === 't') {
+            pg_query($this -> dbconn, "ROLLBACK");
             return "REPLICATED";
         }
 
         $table_name = 'hf_mes_scada_data_capture_node_data_' . $this -> post -> working_subclass;
-        pg_query($this -> dbconn, "BEGIN");
+        // https://www.postgresql.org/docs/current/when-can-parallel-query-be-used.html
         $res[] = pg_query($this -> dbconn, sprintf(
             'CREATE TABLE IF NOT EXISTS "%s" (
                 id serial8,