But what he hasn't told you is that his data set is so large, that while that is the simple solution, painting the screen or whatever the actual issue he's running into is a problem (for him).
Everything indexes only the path and file name, and the search immediately - and you want to look for the size so it will take a bit, how much? depending on how many files - indexing the file size will be in the next version - and now try something else, eg: HDDB.