>In particular, XML is actually miserably bad at capturing certain kinds of >relations between items.
Write examples, please. P.S. By the way, XML is mentioned as tool for traffic (for transport). But i agree to forget about that to learn what are you imply in your quoting. >SQL is not so fantastically hard You don't understand, i speak not about SQL! Problem consist of transportation data, received by SQL, into external world. As i already wrote, it's very difficalt for users (in practice) to use libraries of additional language (php , perl, etc) for that. I offer to put one feature into SQL to avoid mentioned libraries. >why should they not have to do some work to learn how to do those things? For what user agonizes, if it's possible to avoid torments? Assembler turns Fortran by this reason. ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match