AlterQuery  defaults_on_defaults (children 2)
 ExpressionList (children 1)
  AlterCommand ADD_COLUMN (children 1)
   ColumnDeclaration ArrLen (children 2)
    DataType UInt64
    Function length (children 1)
     ExpressionList (children 1)
      Identifier Arr.C4
 Identifier defaults_on_defaults
