partitioning driver

The partitioning driver lets you put different types into different databanks. It lets you defer decisions about database partitioning until configuration time, so you don't have to worry about that kind of thing within your application code.

Usage

To create a partitioning databank, use the Databank.get() method:

var Databank = require('databank').Databank,
    params = {
        'session': {'driver': 'memory', 'params': {}},
        'token': {'driver': 'memcached', 'params': {'serverLocations': ['192.168.3.1:11211', '192.168.3.1:11211']}},
        '*': {'driver': 'mongodb', 'params': {'host': 'myhost.example', 'dbname': 'mydb'}},
    };

var db = Databank.get('partitioning', params);

// Just use databank calls as usual

db.create('session', 123, {nickname: 'evanp', size: 'xl'}, function(err, newSession) {
     console.dir(newSession);
});

// Comes from the default databank

db.read('address', '1444 Elm Street', function(err, readAddress) {
     console.dir(readAddress);
});

Unlike most databank drivers, the partitioning driver doesn't take a fixed set of params.

Instead, the parameters are a map of type names to databank connection definitions with driver and params values. In the above example:

• All session data will be stored in a memory databank
• All token data will be stored in memcached (actually, it could also be Couchbase, but you get the picture)
• All other types will be stored in a mongodb databank.

Note that the special param '*' defines a default driver. You should usually have one, unless you're sure you mapped all your types.

Bugs

• You can only partition vertically by type for now. Horizontal partitioning (by key) will probably happen in the future.
• You can't have a type named '*'. You probably don't need this unless you're a proctologist or an astronomer.
• You can't make two types share the same databank instance.