nice tip about scaling out your database

I was reading the Top Five Scale-Out Pitfalls to Avoid article. I knew about 4 of the 5 techniques that they mentioned, however, this one was new to me

1. Avoid Mixing Hot and Cold Data

   Similar to #3 is mixing hot (frequently-changed) and cold (more static) data, especially when it comes to write activity. Since database writes are more difficult and expensive to scale, it is advisable to keep this type of data away from data that does not change that often. Again, separating the data onto different databases and/or servers can significantly enhance your application's performance.