diff -r 7dd45173f68a -r 285d483db2fb src/server/plugins/postgresql/vfs.c
--- a/src/server/plugins/postgresql/vfs.c	Sat Apr 16 14:36:08 2022 +0200
+++ b/src/server/plugins/postgresql/vfs.c	Sat Apr 16 21:05:29 2022 +0200
@@ -136,6 +136,10 @@
     }
     // resdata will be freed automatically when the request is finished
     
+    return pg_vfs_create_from_resourcedata(sn, rq, resdata);
+}
+
+VFS* pg_vfs_create_from_resourcedata(Session *sn, Request *rq, ResourceData *resdata) {
     // Create a new VFS object and a separate instance object
     // VFS contains fptrs that can be copied from pg_vfs_class
     // instance contains request specific data (PGconn)
@@ -412,7 +416,12 @@
             fd = -2;
         }
         
-        int lo_mode = INV_READ; // TODO: evaluate oflags
+        int lo_mode = INV_READ;
+        if((oflags & O_RDWR) == O_RDWR) {
+            lo_mode = INV_READ|INV_WRITE;
+        } else if((oflags & O_WRONLY) == O_WRONLY) {
+            lo_mode = INV_WRITE;
+        }
         fd = lo_open(pg->connection, oid, lo_mode);
     }