Eric,
> How do I access hierarchical data under PostgreSQL?
> Does it have SQL command similar to Oracle's CONNECT BY?
Joe Conway wrote CONNECT BY as a function. It's in /contrib in your
PostgreSQL source for versions 7.3.0 and above, in /contrib/tablefunc I
think. There is also a different tree implementation in /contrib/ltree.
If that doesn't work for you, there are a number of different solutions to the
tree structure problem, and sample implementations of all of them on
PostgreSQL can be found through the web. Joe Celko covers three of them in
"SQL for Smarties".
--
Josh Berkus
Aglio Database Solutions
San Francisco
