On Tue, Mar 30, 2010 at 8:03 AM, Guillermo Schwarz <[email protected]> wrote: > > SQL can be run on top of a file system (fseek, read, write) or on top of a > persistent hashmap (datastore). > > If you create a SQL interface on top of any of those, then it is a > relational database, not a fake but a real relational database. Why would I > want a relational database? Consistency, for starters. ACID transactions. > Set operations.
...except that you *can't* actually create a performant relational database on top of appengine. Let's be realistic here. There is one reason and one reason only why modern RDBMSes can perform at anything remotely like the speeds necessary for web applications: * Lots and lots of RAM, enough to cache whole indexes. You don't have this in appengine. You get, at best, somewhere around 110 megs. How fast do you think an RDBMS is going to perform on a machine that has been lobotomized to 100 megs of RAM??? If you have an antique computer from the 1990s you can find out. I have no doubt that you can create an RDBMS on top of the GAE datastore. I also have no doubt that trying to tune a Hibernate app to run at reasonable speeds will be a nightmare that I never want to experience. Jeff -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
