Today Dell Boomi released a great new feature – Document Cache.
You can configure a cache on any profile (say a Flat File of all your accounts). You can read in that file in one branch and map it to the cache, and set a key, say account ID.
If for example, you have a process that reads an order from a database or an app such as salesforce.com, you can, in the map step where you are mapping that, add the Cached Data, choose which field in the Order profile to link to the Key in the Cache (Account ID) and it will bring in that profile into the source map. You can then map directly from any of the Order, or matched Account profiles to your target.