I've never had performance issues with nested sets, though I've not used them in an app with super-heavy updates like you describe.
Update performance is bound by the number of nodes in the tree, of course, so if you have 400 sites with 100 trees each, but each tree is only 50 nodes, it's the 50 that matters, not the 40,000. I don't know what your estimated tree size is, but that'd be the question to ask, rather than the horizontal scaling. It would be easy to do some load testing to see what the results would be with different tree sizes. Though if you care about the performance of the event responses, the bennies of nested sets on the front end might be worth a a little lag on the back end. Totally app/customer specific, of course. And make sure you have fast disks. DB IO has been the limiting factor (not RAM or CPU) on the last couple apps I've worked on, and optimizing that is a bitch. Don't know if that helps, but I wouldn't rule our nested sets without some good numbers. I've found MSSQL to be lickety-split, in general. Though now that I'm thinking about it, you might run some load tests with adjacency lists for storage (fast update) and recursive CTEs for recall. I haven't done recursion that way a whole lot, but the few times I've used it, I've been quite pleased with performance, even with fairly large, deep trees. cheers, barneys --- Barney Boisvert [EMAIL PROTECTED] http://www.barneyb.com On Sep 17, 2008, at 9:30 PM, "Mike Kear" <[EMAIL PROTECTED]> wrote: > I'm designing an application that will require a whole series of > heirarchies - its an action plan where the plans can be quite complex. > The idea is a business event happens (a sale or a project is started > ) and that triggers a whole set of events that must follow. > > I'm thinking of using nested sets to lay out the heirarchies of > events, because they are so flexible adn its so easy to move things > about with them. But i'm a bit worried about how it might perform > under load. > > I've used nested sets for ages in my CMS and had no problems at all. > But you dont make hundreds of updates a day to a CMS node structure. > Has anyone used an application using nested sets where there are lots > of updates a day? Did it perform ok? > > My environment is Windows2003, CF7, MSSQLServer. We are > provisioned ok for RAM and processor capacity, but dont want to clog > it with too much activity from any one application. There are 400+ > offices using this site - it's an extranet app. > > Can anyone give me any experience with nested sets and > coldfusion/MSSQLServer with volumes of updates like that? > > -- > Cheers > Mike Kear > Windsor, NSW, Australia > Adobe Certified Advanced ColdFusion Developer > AFP Webworks > http://afpwebworks.com > ColdFusion, PHP, ASP, ASP.NET hosting from AUD$15/month > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Adobe® ColdFusion® 8 software 8 is the most important and dramatic release to date Get the Free Trial http://ad.doubleclick.net/clk;203748912;27390454;j Archive: http://www.houseoffusion.com/groups/CF-Talk/message.cfm/messageid:312744 Subscription: http://www.houseoffusion.com/groups/CF-Talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
