--- a/src/StreamRelationalWriter.h	Mon Sep 03 23:41:29 2018 +0200
+++ b/src/StreamRelationalWriter.h	Sun Sep 09 23:20:57 2018 +0200
@@ -9,6 +9,7 @@
 #include "../include/relpipe/writer/typedefs.h"
 #include "../include/relpipe/writer/RelationalWriter.h"
 #include "../include/relpipe/writer/TypeId.h"
+#include "../include/relpipe/writer/AttributeMetadata.h"
 #include "DataTypeWriterBase.h"
 #include "types/BooleanDataTypeWriter.h"
 #include "types/IntegerDataTypeWriter.h"
@@ -62,7 +63,7 @@
 		throw RelpipeWriterException(L"Unsupported data type: " + typeCode);
 	}
 
-	void startRelation(string_t name, std::vector<std::pair<string_t, TypeId> > attributes, boolean_t writeHeader) override {
+	void startRelation(string_t name, std::vector<AttributeMetadata> attributes, boolean_t writeHeader) override {
 		string_t tableName = name;
 		columnCount = attributes.size();
 		currentColumn = 0;
@@ -77,13 +78,13 @@
 
 		// Write column names:
 		for (size_t c = 0; c < columnCount; c++) {
-			wstring columnName = attributes[c].first;
+			wstring columnName = attributes[c].attributeName;
 			stringWriter.writeValue(output, columnName);
 		}
 
 		// Write column types:
 		for (size_t c = 0; c < columnCount; c++) {
-			TypeId typeId = attributes[c].second;
+			TypeId typeId = attributes[c].typeId;
 			integerWriter.writeValue(output, static_cast<integer_t> (typeId));
 			columnTypes[c] = typeId;
 		}