From c2455e1182dcff9c4d8f849d6f5f608e0b09dda7 Mon Sep 17 00:00:00 2001
From: Michael Kolupaev <mkolupaev@yandex-team.ru>
Date: Fri, 21 Jun 2013 10:36:01 +0000
Subject: [PATCH] clickhouse: fixed ExpressionAnalyzer [#CONV-7444].

---
 dbms/src/Interpreters/ExpressionAnalyzer.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/dbms/src/Interpreters/ExpressionAnalyzer.cpp b/dbms/src/Interpreters/ExpressionAnalyzer.cpp
index a9d51a5f317..89a451a13a4 100644
--- a/dbms/src/Interpreters/ExpressionAnalyzer.cpp
+++ b/dbms/src/Interpreters/ExpressionAnalyzer.cpp
@@ -1027,18 +1027,21 @@ void ExpressionAnalyzer::removeUnusedColumns()
 	if (required.empty())
 		required.insert(ExpressionActions::getSmallestColumn(columns));
 	
+	unknown_required_columns = required;
+	
 	for (NamesAndTypesList::iterator it = columns.begin(); it != columns.end();)
 	{
 		NamesAndTypesList::iterator it0 = it;
 		++it;
+		
+		unknown_required_columns.erase(it0->first);
+		
 		if (!required.count(it0->first))
 		{
 			required.erase(it0->first);
 			columns.erase(it0);
 		}
 	}
-	
-	unknown_required_columns = required;
 }
 
 Names ExpressionAnalyzer::getRequiredColumns()