As I was reading up about couchdb I stumbled upon a question about transactions and couchdb. Apparently the way to handle transactions in couch is to pull the latest version and compare it to the version you are currently working with. This can present problems if data is changing quickly. The other way is a map reduce and to separate out the transactional data into multiple documents. This also seems less than optimal.
I was thinking about using redis for this sort of data. The increment and decrement functions seem fairly amazing for this sort of purpose.
So I could just write some sort of string for a transactional key like:
//some user document
{
name: "guy",
id: 10,
page_views: "redis user:page_views:10"
}
Then if I read something like "redis" inside of some piece of transactional data then I know to go get that information from redis. I suppose I could decide these things before hand, but since a document oriented database's primary mission is to be flexible and not bound data to columns I figured that there might be an easier way?
Is there an easy way to link redis data to couchdb? should I be doing this all manually and for the few fields that come up? Any other thoughts? Would it be better to update this transactional data "eventually" in the user document or simply not store it there?
Both Redis and CouchDB are "easy" (that is, simple). So in that regard, what you are describing is easy. Of course, by using two databases, you have increased the complexity of your application. But on the other hand, the CouchDB+Redis combination is gaining popularity.
The only tool I know that integrates the two is Mikeal Rogers's redcouch. It is a simple tool. Perhaps you could extend it to add what you need (and send a pull request!).
A more broad consideration is that Redis does not have the full replication feature set that CouchDB does. So Redis might restrict your future options with CouchDB. Specifically, Redis does not support multi-master replication. In contrast with CouchDB, you will always have a centralized Redis database. (Correct me if I'm wrong—I am stronger with CouchDB than with Redis.)