Rob, > Yes. With this you can find all part numbers/supplies which match your > value, wattage criteria in one table. Or exclude any which have a > non-null is_replacement_for value.
I understand -- thanks. I have received contradictory advice in a purely data modeling context. What about the null values that will be in the properties columns of the part? It would appear to be more applicable to an employee database where the columns are populated regardless and the "replacement_for" in the context of our discussion would be a self-reference to the employee's manager. No? Thanks again for your help. -- Gary Chambers -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
