diff --git a/dbms/include/DB/Columns/ColumnFixedString.h b/dbms/include/DB/Columns/ColumnFixedString.h
index 0c1db840714..da2cfbc5e4f 100644
--- a/dbms/include/DB/Columns/ColumnFixedString.h
+++ b/dbms/include/DB/Columns/ColumnFixedString.h
@@ -15,7 +15,6 @@ namespace DB
 class ColumnFixedString : public IColumn
 {
 public:
-	//typedef std::vector<UInt8> Chars_t;
 	typedef PODArray<UInt8> Chars_t;
 
 private:
@@ -78,7 +77,7 @@ public:
 			throw Exception("Too large string '" + s + "' for FixedString column", ErrorCodes::TOO_LARGE_STRING_SIZE);
 		
 		size_t old_size = chars.size();
-		chars.resize(old_size + n);
+		chars.resize_fill(old_size + n);
 		memcpy(&chars[old_size], s.data(), s.size());
 	}
 
@@ -103,7 +102,7 @@ public:
 
 	void insertDefault()
 	{
-		chars.resize(chars.size() + n);
+		chars.resize_fill(chars.size() + n);
 	}
 
 	int compareAt(size_t p1, size_t p2, const IColumn & rhs_, int nan_direction_hint) const
diff --git a/dbms/include/DB/Common/PODArray.h b/dbms/include/DB/Common/PODArray.h
index 905fa9e46d9..f762476257f 100644
--- a/dbms/include/DB/Common/PODArray.h
+++ b/dbms/include/DB/Common/PODArray.h
@@ -208,6 +208,18 @@ public:
 		c_end = c_start + byte_size(n);
 	}
 
+	/// Как resize, но обнуляет новые элементы.
+	void resize_fill(size_t n)
+	{
+		size_t old_size = size();
+		if (n > old_size)
+		{
+			reserve(n);
+			memset(c_end, 0, n - old_size);
+		}
+		c_end = c_start + byte_size(n);
+	}
+
 	void clear()
 	{
 		c_end = c_start;
diff --git a/dbms/src/Columns/ColumnConst.cpp b/dbms/src/Columns/ColumnConst.cpp
index 6d655761939..3a25e47aafa 100644
--- a/dbms/src/Columns/ColumnConst.cpp
+++ b/dbms/src/Columns/ColumnConst.cpp
@@ -45,7 +45,7 @@ template <> ColumnPtr ColumnConst<String>::convertToFullColumn() const
 		ColumnPtr res_ptr = res;
 		ColumnFixedString::Chars_t & vec = res->getChars();
 
-		vec.resize(n * s);
+		vec.resize_fill(n * s);
 		size_t offset = 0;
 
 		for (size_t i = 0; i < s; ++i)