diff --git a/code/database/mongo/migrations/gan_rao_ma.php b/code/database/mongo/migrations/gan_rao_ma.php
new file mode 100644
index 0000000..e12b9a1
--- /dev/null
+++ b/code/database/mongo/migrations/gan_rao_ma.php
@@ -0,0 +1,10 @@
+<?php
+return [
+    'collection' => 'gan_rao_ma',
+    'indexes' => [
+        [
+            'key' => ['grm_domain' => 1, 'grm_page_code' => 1, 'grm_page_line' => 1, 'grm_page_diff' => 1],
+            'options' => ['unique' => true]
+        ],
+    ]
+];