CreateQuery lc_null_fix_str_0 (children 3)
 Identifier lc_null_fix_str_0
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration str (children 1)
    DataType LowCardinality (children 1)
     ExpressionList (children 1)
      DataType Nullable (children 1)
       ExpressionList (children 1)
        DataType FixedString (children 1)
         ExpressionList (children 1)
          Literal UInt64_2
 Storage definition (children 1)
  Function Memory