Efficient ways to make Rating scripts?
So this has been bobbled up in my head for quite some time: What other ways are there to create an efficient rating script?
So here are the only ways I've thought of, visavi MySQL:
1) Constantly summing the ratings and dividing it by the total amount of ratings available in a table. This is, in my opinion, the slowest way to do things.
2) Have two fields in a table called ratingSum and totalRaters, where you can just do ratingSum/totalRaters. This is the faster way, but I think that it isn't as "nice"
What would be more efficient than #2?