On 3/1/07, Kenneth Downs <ken@xxxxxxxxxx> wrote:
Better? I think perhaps different. There is materialized path, which requires a very problematic unlimited-length column to hold the path, and there is upper/lower bounds, which again requires client-side row-by-row processing. Both have the unpleasant problem that changes to one row may affect many others.
there are also other approaches. i know that they are not that well known, but there are, and they allow many things to be done with very simple queries. i use a solution which basically allows me to query every kind of tree-structure data without loops or recursion. drawbacks are 2 and are very limited: 1. it uses some triggers 2. it has some (slight in my opinion) overhead. i wrote an article about it here (http://www.depesz.com/various/various-sqltrees-implementation.php). it's in polish, but has lots of examples so should be easily readable. depesz
