On Thu, Jun 30, 2011 at 3:02 AM, Svetlin Manavski < svetlin.manav...@gmail.com> wrote:
> I am now a bit puzzled after the initial satisfaction by Marinos' reply. > > 1. what do you mean exactly by "to ensure your UNION succeeds". The dblink > docs do not mention anything about issues using directly the suggested > dblink_send_query() + dblink_get_results(). What problems should I expect in > using them as suggested by Marinos? > > Admittedly, I hadn't used those specific dblink functions and imagined dblink_get_result() failing if the query on the connection wasn't finished. It appears now that after some experimentation that it's perfectly happy hanging until the query is finished executing. > 2. If I understand correctly your method, it is not applicable from inside > a stored procedure, is it? I need to keep all the business logic within > PostgreSQL and provide just a clean interface to a simple GUI layer > > Then dblink is your answer. My suggestion applies if you were implementing a solution in the application. > 3. Unfortunately GridSQL and Pgpool-II do not seem mature and stable > products to be used in commercial software. Neither one provides clear > documentation. GridSQL has been discontinued and it is not clear what kind > of future it will have. I have not tried GridSQL but I did try Pgpool-II. It > is disappointing that it may stop working correctly even just because of the > way you write the query (e.g. using uppercase in a field or using named > field in group by, ecc.). Even worse, when it does not recognize something > in the parallel query, it just provides incorrect result (from only the > local DB) rather than raising an exception. So I guess Pgpool-II in its > current state is good only for very simple applications, which are not > supposed to be reliable at all. > > I don't think GridSQL is discontinued. Appears though EnterpriseDB has open sourced it and moved to http://sourceforge.net/projects/gridsql/. Not incredibly active but some as recent as last month. Sorry for the confusion. Greg
