[davisp]

The main two reasons that CouchDB doesn't use multiple files per database are system limits and increased complexity.

CouchDB has a bit of an alternative design in that it accepts that people might be running a large number of databases on a single node. I don't remember the exact numbers but I think we've heard of deploys using 10-100K (small) db's on a single node.

As to complexity, with a single file, there's no magical fsync dance to coordinate when committing data to disk. Its not unpossible, its just more complex.

Its not out of the question that CouchDB will move to using multiple files per database, but as its open source, the biggest road block so far is that no one's needed it badly enough to implement it.

[rch]

I've noticed that interesting things tend to show up in bigcouch before couchdb. So, if I were starting a couchdb based project today, it would be with cloudant.