Hi Guillermo, I agree with you completely. Here are my thoughts on the subject.
Relational theory, SQL and JDBC are functional specifications and RDBMS vendors implement these specifications. Actually speaking data model has nothing to do with technology. A data model in software engineering is an abstract model that describes how data is represented and accessed. Data models formally define data elements and relationships among data elements for a domain of interest. The tools which extrapolate proper strategy for storing and accessing data on the underlying datastore based on the data model and expose it via SQL and JDBC in both client/server and server mode have a great advandage. This is our goal at Cloud2db. This abstraction layer also gives you complete flexibility of choosing your underlying datastore. For example, we are about to release Cloud2db Amazon SimpleDB and Hadoop Hbase implementations soon. Thanks, Sandeep. On Tue, Mar 30, 2010 at 11:03 AM, Guillermo Schwarz < guillermo.schw...@gmail.com> wrote: > Andreas, > > I think there is more misunderstanding again. > > 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. > > Read: > 1. http://www.buzzle.com/articles/advantages-of-relational-databases.html > 2. http://www.sunadal.co.uk/db.php > 3. http://www.euclideanspace.com/software/information/relational/index.htm > > Working directly with aseembly code and bits may be what you prefer, but if > history is correct, computer science is about building abstractions. Good > abstractions. I agree that you can create the wrong tools for the job, but > that doesn't stop other people to investigate and innovate to create better > tools (better abstractions). > > BTW: You dont need to use JDBC directly when working with CloudDB or jiql. > You can always select Hibernate, JDO or even JPA. The advantage of using an > extra level of abstraction is that if later the DataStore changes or there > is a new alternative to the DataStore that is faster (but has a new API) all > you need to do is to reimplement SQL on top of it and voila: All your > applications have been ported effortlessly. That's the whole point of using > abstraction layers. > > Cheers, > Guillermo. > > > On Tue, Mar 30, 2010 at 10:49 AM, Andreas Borglin < > andreas.borg...@gmail.com> wrote: > >> >> Ok, you seem to misunderstand me quite a bit here. >> >> I never said it can't be used. I just said that I don't want to. >> Other than for portability reasons, why would I want to pretend that >> the datastore is relational by using a framework that emulates this? >> >> My main requirement, which was formed after using j...@gae, is that I >> want to use a framework that has a natural mapping to the datastore. >> >> I'm not saying that there is anything wrong with JDO/JPA, cloud2db or >> jiql in general. I'm just saying that, for me, it makes more sense to >> use a framework that exposes the true nature of the datastore (which >> is very different from a relational database), instead of hiding it >> under a portable abstraction layer. Simplicity and performance is more >> important than portability for me. That is of course not true for many >> other projects, so I'm only speaking from my perspective. >> >> If you can argue that jiql (or any other multi-platform framework like >> cloud2db, etc) can provide a natural mapping to the datastore AND be >> as efficient as the low-level wrappers, I'm all ears. j...@gae didn't >> do it for me at least. >> >> I never said that GWT had anything to do with SQL. I just don't want >> to use JDBC. >> >> On Mar 30, 3:51 pm, Guillermo Schwarz <guillermo.schw...@gmail.com> >> wrote: >> > Andreas, >> > >> > I don't get it. You can use JDO and Hibernate with SQL. Given that >> > jiql has a Hibernate config file, I guess using Hibernate with jiql >> > would be so easy. >> > >> > What does GWT and JSP have to do with SQL anyway? >> > >> > Cheers, >> > Guillermo. >> > >> > On 30 mar, 03:51, Andreas Borglin <andreas.borg...@gmail.com> wrote: >> > >> > >> > >> > > Hi again. >> > >> > > I had a look at jiql. >> > > "jiql is a JDBC wrapper for accessing Google DataStore on Google App >> > > Engine for JAVA. >> > > jiql supports the use of standard SQL as a method for accessing >> > > the DataStore" >> > >> > > Even if I had seen jiql earlier I wouldn't have considered it anyway >> > > because, >> > >> > > 1. I want the API to make perfect sense for working with the >> > > datastore. "Standard SQL" doesn't meet this requirement. >> > > 2. I use GWT. Not JSP or any other technology to dynamically generate >> > > pages on server side. >> > >> > > On Mar 29, 8:52 pm, Guillermo Schwarz <guillermo.schw...@gmail.com> >> > > wrote: >> > >> > > > One question: Why didn't you consider jiql? >> > >> > > > On Mon, Mar 29, 2010 at 1:04 PM, Blake <blakecaldw...@gmail.com> >> wrote: >> > > > > +1 >> > >> > > > > On Mar 29, 4:03 am, Andreas Borglin <andreas.borg...@gmail.com> >> wrote: >> > > > > > Hi all. >> > >> > > > > > I recently decided to migrate away from JDO to one of the third >> party >> > > > > > datastore frameworks. At first I had only heard about objectify, >> but >> > > > > > after some further digging I found out about 5 other frameworks >> as >> > > > > > well (Twig, SimpleDS, siena, slim3, cloud2db). >> > >> > > > > > I was only interested in simple wrapper frameworks that acted as >> a >> > > > > > convenience layer above the AppEngine low-level API. I _want_ >> the >> > > > > > framework to expose the true nature of the datastore, but at the >> same >> > > > > > time relieve the developer of the tedious tasks that's involved >> when >> > > > > > working with the low-level API directly. It is much easier to >> work >> > > > > > with the AppEngine datastore when its concepts, features, >> constraints >> > > > > > and limitations are exposed directly. You can read more about >> the >> > > > > > reasons for this in the article. >> > >> > > > > > This left me with objectify, Twig and SimpleDS. (siena and >> cloud2db >> > > > > > are multi-platform and slim3 is more than just a datastore >> framework) >> > >> > > > > > I spent some time researching these when I got the idea to write >> an >> > > > > > article about them. I contacted the authors for each framework >> and >> > > > > > asked if they would be interested in participating. Passionate >> as they >> > > > > > are, they agreed :-). Thanks to Jeff Schnitzer (objectify), John >> > > > > > Patterson (Twig) and Ignacio Coloma (SimpleDS) for this. >> > >> > > > > > The goal is to publish two articles; one interview with the >> authors, >> > > > > > and one where I solve some typical scenario with each framework. >> > > > > > The interview article has now been published and can be found >> athttp:// >> > > > > borglin.net/gwt-project/?page_id=604. >> > > > > > The code example article will be posted sometime in the upcoming >> two >> > > > > > weeks. >> > >> > > > > -- >> > > > > 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 >> > > > > google-appengine-j...@googlegroups.com. >> > > > > To unsubscribe from this group, send email to >> > > > > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com><google-appengine-java%2B >> unsubscr...@googlegroups.com> >> > > > > . >> > > > > For more options, visit this group at >> > > > >http://groups.google.com/group/google-appengine-java?hl=en. >> > >> > > > -- >> > > > Saludos cordiales, >> > >> > > > Guillermo Schwarz >> > > > Sun Certified Enterprise Architect >> >> -- >> 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 >> google-appengine-j...@googlegroups.com. >> To unsubscribe from this group, send email to >> google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-appengine-java?hl=en. >> >> > > > -- > Saludos cordiales, > > Guillermo Schwarz > Sun Certified Enterprise Architect > > -- > 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 > google-appengine-j...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. 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