First off, I'm not saying it's better. It's heavy, complicated, incredibly expensive, the really cool features are even more expensive, but feature-wise, it's an amazing example of what you can do inside of a relational database engine if you have years and years and billions of dollars to spend on R&D.
To answer your questions:
> Does it have multi-master replication like CouchDB?
Yes! It has several kinds of replication. Active/passive, active/passive with the standby available for reading, multi-master, cascading replication (master->standby->secondary standby). You can also do combinations of the above, like master<->master->standby<-master->standby->standby (if you want to get really crazy).
But it's a lot more than that. Synchronous? Sure. Asynchronous? Sure. Semi-synchronous? Yes, I can say that I want to allow the standby database to get up to X minutes out of sync with the primary before I switch over to synchronous and force clients to block until I'm caught up.
Hey, what about file-based replication for items that are not even technically managed by Oracle or inside the database? No problem.
What about failover? Well, Oracle can not only have its clients detect that a database has failed and handle the failover automatically, but you can actually have it fail over and automatically spin up another standby so you don't have a SPOF.
I could go on for pages just on replication scenarios that Oracle supports.
> What about append-only storage of data (so can do live backup snapshots)?
Yes, absolutely, but to be honest, you don't need append-only storage to do live backup snapshots in Oracle. You can do point-in-time consistent backups while the database is serving transactions (it works under the covers similarly to append-only, but the nuances are a little different). Not only can you run backups this way, but you can actually request that your session "see" a view of the database as it was an hour or a day ago. You can also simply say, "return the database to the state it was as of X transaction or at Y time", and the entire database can revert back to that state.
> Or a REST-ful interface (so can directly use it from web clients, via a simple proxy)? A web based data browser and viewer like Futon?
Yes, Oracle APEX, which is basically an Oracle front-end application server, but lighter than a "real" J2EE stack, can do both of these things. If you want, there's a fairly simple markup language, similar to ERB, that you can use to write simple CRUD rails-like applications on top of APEX, but you don't have to if you don't want to.
Again, I'm not saying that Oracle is better, because all of these features come at a complexity cost that is massive (and a technical debt that requires highly skilled specialty technologists). If I were building an application today, I would not base it on Oracle, because for what 90% of the world needs, there are open source databases or data stores that fill the need just fine. But you gotta hand it to Oracle for the sheer amount of technology they've crammed into an RDBMS.
Thanks for responding. I had no idea about these features. Well heck you can say it is better. That would be alright.
I have been living in the open source world and just never had to deal with commercial DBs at this point.
So I agree with your point. A lot of these features are there but up coming developers might not know about it and will always pick open source choices.
I guess PostgreSQL is the direct competitor at the moment and I have only heard good things about, and Oracle is hated by large numbers of developers (for reasons not necessarily related to technical features).
To answer your questions:
> Does it have multi-master replication like CouchDB?
Yes! It has several kinds of replication. Active/passive, active/passive with the standby available for reading, multi-master, cascading replication (master->standby->secondary standby). You can also do combinations of the above, like master<->master->standby<-master->standby->standby (if you want to get really crazy).
But it's a lot more than that. Synchronous? Sure. Asynchronous? Sure. Semi-synchronous? Yes, I can say that I want to allow the standby database to get up to X minutes out of sync with the primary before I switch over to synchronous and force clients to block until I'm caught up.
Hey, what about file-based replication for items that are not even technically managed by Oracle or inside the database? No problem.
What about failover? Well, Oracle can not only have its clients detect that a database has failed and handle the failover automatically, but you can actually have it fail over and automatically spin up another standby so you don't have a SPOF.
I could go on for pages just on replication scenarios that Oracle supports.
> What about append-only storage of data (so can do live backup snapshots)?
Yes, absolutely, but to be honest, you don't need append-only storage to do live backup snapshots in Oracle. You can do point-in-time consistent backups while the database is serving transactions (it works under the covers similarly to append-only, but the nuances are a little different). Not only can you run backups this way, but you can actually request that your session "see" a view of the database as it was an hour or a day ago. You can also simply say, "return the database to the state it was as of X transaction or at Y time", and the entire database can revert back to that state.
> Or a REST-ful interface (so can directly use it from web clients, via a simple proxy)? A web based data browser and viewer like Futon?
Yes, Oracle APEX, which is basically an Oracle front-end application server, but lighter than a "real" J2EE stack, can do both of these things. If you want, there's a fairly simple markup language, similar to ERB, that you can use to write simple CRUD rails-like applications on top of APEX, but you don't have to if you don't want to.
Again, I'm not saying that Oracle is better, because all of these features come at a complexity cost that is massive (and a technical debt that requires highly skilled specialty technologists). If I were building an application today, I would not base it on Oracle, because for what 90% of the world needs, there are open source databases or data stores that fill the need just fine. But you gotta hand it to Oracle for the sheer amount of technology they've crammed into an RDBMS.