diff -r dad72beb3ebe -r 16784291982f src/QtRelationalReaderStringHadler.h
--- a/src/QtRelationalReaderStringHadler.h	Sat Sep 29 14:14:00 2018 +0200
+++ b/src/QtRelationalReaderStringHadler.h	Sun Sep 30 01:40:29 2018 +0200
@@ -56,6 +56,8 @@
 
 private slots:
 
+	// FIXME: asynchronous signal-slot data passing between two threads
+
 	void slot_startRelation(string_t name, std::vector<AttributeMetadata> attributes) {
 		target->startRelation(name, attributes);
 	};