Importance-based caching

[Lars Schöning]

Hello,
I'm new to the MEMORY engine, but see it as an important part of a system I am currently developing. I have a lot of small chunks of data that are hard to compute and are heavily reused. Because the cache should only work with the most frequently used entries, I have developed a ranking system for the data.

Now I am looking for a method to keep a table always completely filled with the highest ranked data. My problem here is that I don't know how one would go about replacing low ranked data only when the table is full and what exactly will happen when the table has filled up as such.