The datastore implementation (non-relational) is one of the last things I'm bumping against (now Java is supported ;-)
I understand that aggregate data *can* be calculated at write time. But this is not what I want and I guess a lot of other users will think the same. Also adhoc querying will be difficult with the current datastore. Maybe I want the sum of revenue per User or the sum of all users or maybe the sum per Country or, City, or... this would mean a lot of calculations to be done. IMHO this is also very error prone. And maybe someday our business department wants average figures instead of sums... I guess Amazon is not for nothing offering persistent storage which allows user to use e.g. MySQL. Also Sun's Cloud features a relational database (again MySQL). I think 95% of all developers attracted to Google App Engine are using relational databases in the daily job... Like Andrew said it's a issue of barrier. PS: I will look into the index documentation to see if it can help me with aggregate data. Cheers, Marcel On 8 apr, 21:40, Dan Sanderson <dansander...@google.com> wrote: > Some of the same problems can be solved in different ways. For instance, > aggregate data can often be calculated at write time, obviating the need for > an expensive aggregate runtime query involving millions of records and > hundreds of machines. The tricky bit is implementing the different > solutions using compatible APIs, which isn't always possible. > > -- Dan > > On Wed, Apr 8, 2009 at 12:31 PM, Marcel Overdijk > <marceloverd...@gmail.com>wrote: > > > > > > > Maybe for performance the datastore as it is now is best. > > But when working with data (e.g. aggregate functions like sum, avg > > etc.) a relational database has also advantages. > > > On 8 apr, 19:58, Andrew Badera <and...@badera.us> wrote: > > > It might not make "sence" but it certainly makes "sense" when you're > > living > > > in a world full of RDBMS, and want to make the barrier to entry as low as > > > possible. > > > > Thanks- > > > - Andy Badera > > > - and...@badera.us > > > - Google me:http://www.google.com/search?q=andrew+badera > > > > Sent from Albany, NY, United States > > > > On Wed, Apr 8, 2009 at 1:56 PM, Barry Hunter < > > barrybhun...@googlemail.com>wrote: > > > > > similar, but it wouldnt make sence to have two database backends.- > > Tekst uit oorspronkelijk bericht niet weergeven - > > > > - Tekst uit oorspronkelijk bericht weergeven -- Tekst uit oorspronkelijk > > > bericht niet weergeven - > > - Tekst uit oorspronkelijk bericht weergeven - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
