Hi Vladan,

The general idea is to get the data in the cache whenever the need arises. It certainly does not mean that if I have a TB of data file, then I would have to have that much of RAM, but when I have a database where I am getting frequent performance problem and I want to troubleshoot the issue, then I would certainly look into the rule of thumb. If I have a 8GB data file and 8GB of memory, I would assume that the memory is OK, and jump into the other aspects, like CPU, Network or Disk for troubleshooting.

On the other side, I have given some perfmon counters which will help you to identify if you really require additional memory. The rule of thumb is just to give you a hint to look for when you do not have adequete time for investigation.

Hope this clarifies the issue.

Thanks for taking time to read and give your valuable feedback.

~Arindam.