CreateQuery 01754_dictionary_db complex_key_complex_attributes_source_table (children 4)
 Identifier 01754_dictionary_db
 Identifier complex_key_complex_attributes_source_table
 Columns definition (children 1)
  ExpressionList (children 4)
   ColumnDeclaration id (children 1)
    DataType UInt64
   ColumnDeclaration id_key (children 1)
    DataType String
   ColumnDeclaration value_first (children 1)
    DataType String
   ColumnDeclaration value_second (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType String
 Storage definition (children 2)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList
