Hi all. I need to implement a (classical) categorization of items accordingly to a tree-like hierarchy. I mean, I have a tree describing the hierarchy itself. Then I need to link each item to one or more categories. Later I may be asked to select all items belonging to one or more categories or any of the descendants. At the moment I'm not aware of any limitation on the hierarchy depth. What I know is: 1. the category tree won't change very often; 2. the relation between products and categories will also be rather static. I've found very interesting the ltree TYPE (http://www.postgresql.org/docs/current/static/ltree.html) as well as a number of other SQL-based solution like the WITH RECURSIVE predicate. My questions: 1. What would it be a good solution in terms of query speed in this context? 2. Why that one would be better than the others? 3. If the solution is ltree, would it make any sense (and why) to use wither GIN or GiST indexing? I'll appreciate also any link to documentation or discussions about this topic. Thanks. -- Vincenzo Romano at NotOrAnd Information Technologies Software Hardware Networking Training Support Security -- NON QVIETIS MARIBVS NAVTA PERITVS -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
