On Sun, 11 Aug 2002, Don Baccus wrote: > It's just type extensibility, really.
Yeah. > As to why, again there's an efficiency argument, as I said earlier some > joins can be avoided given PG's implementation of this feature: > [TI and relational examples deleted] What you gave is not the relational equivalant of the TI case as implemented in postgres. Modeled correctly, you should be creating a table for the child, and a view for the parent. Then you will find that the relational definition uses or avoids joins exactly where the TI definition does. > There's also some error checking (using my inherited example): The relational definition doesn't force the dependency, but as you can delete and recreate the view at will without data loss, the amount of safety is the same. cjs -- Curt Sampson <[EMAIL PROTECTED]> +81 90 7737 2974 http://www.netbsd.org Don't you know, in this new Dark Age, we're all light. --XTC ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
