diff --git a/src/LogMgr.cc b/src/LogMgr.cc
index 0b706f6417..28e9a2ac1f 100644
--- a/src/LogMgr.cc
+++ b/src/LogMgr.cc
@@ -81,16 +81,18 @@ struct LogMgr::Stream {
 bool LogField::Read(SerializationFormat* fmt)
 	{
 	int t;
+	int st;
 
-	bool success = (fmt->Read(&name, "name") && fmt->Read(&t, "type"));
+	bool success = (fmt->Read(&name, "name") && fmt->Read(&t, "type") && fmt->Read(&st, "subtype") );
 	type = (TypeTag) t;
+	subtype = (TypeTag) st;
 
 	return success;
 	}
 
 bool LogField::Write(SerializationFormat* fmt) const
 	{
-	return (fmt->Write(name, "name") && fmt->Write((int)type, "type"));
+	return (fmt->Write(name, "name") && fmt->Write((int)type, "type") && fmt->Write((int)subtype, "subtype"));
 	}
 
 LogVal::~LogVal()
@@ -707,6 +709,14 @@ bool LogMgr::TraverseRecord(Stream* stream, Filter* filter, RecordType* rt,
 		LogField* field = new LogField();
 		field->name = new_path;
 		field->type = t->Tag();
+		if ( field->type == TYPE_TABLE ) 
+			{
+				field->subtype = t->AsSetType()->Indices()->PureType()->Tag();
+			} 
+		else if ( field->type == TYPE_VECTOR ) 
+			{
+				field->subtype = t->AsVectorType()->YieldType()->Tag();
+			}
 		filter->fields[filter->num_fields - 1] = field;
 		}
 
diff --git a/src/LogMgr.h b/src/LogMgr.h
index 10530960cb..3eaba360d5 100644
--- a/src/LogMgr.h
+++ b/src/LogMgr.h
@@ -15,10 +15,12 @@ class SerializationFormat;
 struct LogField {
 	string name;
 	TypeTag type;
+	// inner type of sets
+	TypeTag subtype;
 
-	LogField()	{ }
+	LogField() 	{ subtype = TYPE_VOID; }
 	LogField(const LogField& other)
-		: name(other.name), type(other.type)	{ }
+		: name(other.name), type(other.type), subtype(other.subtype) {  }
 
 	// (Un-)serialize.
 	bool Read(SerializationFormat* fmt);
diff --git a/src/LogWriterAscii.cc b/src/LogWriterAscii.cc
index 9b1fda3b62..0213f52adb 100644
--- a/src/LogWriterAscii.cc
+++ b/src/LogWriterAscii.cc
@@ -125,6 +125,12 @@ bool LogWriterAscii::DoInit(string path, int num_fields,
 			const LogField* field = fields[i];
 			names += field->name;
 			types += type_name(field->type);
+			if ( (field->type == TYPE_TABLE) || (field->type == TYPE_VECTOR) )
+				{
+					types += "[";
+					types += type_name(field->subtype);
+					types += "]";
+				}
 			}
 
 		if ( ! (WriteHeaderField("fields", names)