Key-Value Stores in Ruby (Key-Value Stores Part 1) | Engine Yard Blog

Key-Value Stores in Ruby | Engine Yard Blog:

While PStore lets you store anything that can be marshaled, it does have some notable performance restrictions. It's a simple piece of kit, so when a transaction is opened on a store, it doesn't do anything sophisticated; it reads the whole store into memory. This makes it useless for huge data sets that you would not or could not otherwise store in RAM, and it also makes opening and closing any large data store an expensive operation. Whether the expense is greater than that incurred by a traditional relational database will depend on the individual use cases, but for larger data sets it becomes completely untenable as a solution. In those cases, you need to look a relational database or more sophisticated key-value stores.

Full article: http://www.engineyard.com/blog/2009/key-value-stores-in-r...