Not just disk space, larger index size mean less fits in caches and memory, more I/O etc. These are keys which are typically used constantly by an app in the d

Not just disk space, larger index size mean less fits in caches and memory, more I/O etc. These are keys which are typically used constantly by an app in the db with joins etc. They are some of the hottest data typically and you want to avoid cache misses on them if possible.