CreateQuery enum_nested_alter (children 3)
 Identifier enum_nested_alter
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration d (children 2)
    DataType Date
    Literal \'2000-01-01\'
   ColumnDeclaration x (children 1)
    DataType UInt64
   ColumnDeclaration tasks (children 1)
    DataType Nested (children 1)
     ExpressionList (children 2)
      NameTypePair errcategory (children 1)
       DataType Enum8 (children 1)
        ExpressionList (children 9)
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'undefined\'
           Literal UInt64_0
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'system\'
           Literal UInt64_1
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'generic\'
           Literal UInt64_2
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'asio.netdb\'
           Literal UInt64_3
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'asio.misc\'
           Literal UInt64_4
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'asio.addrinfo\'
           Literal UInt64_5
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'rtb.client\'
           Literal UInt64_6
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'rtb.logic\'
           Literal UInt64_7
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'http.status\'
           Literal UInt64_8
      NameTypePair status (children 1)
       DataType Enum16 (children 1)
        ExpressionList (children 2)
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'hello\'
           Literal UInt64_1
         Function equals (children 1)
          ExpressionList (children 2)
           Literal \'world\'
           Literal UInt64_2
 Storage definition (children 1)
  Function MergeTree (children 1)
   ExpressionList (children 3)
    Identifier d
    Identifier x
    Literal UInt64_1