How to tell someone has no idea what they're talking about:
(note: context is talking about SHA hashes for the purpose of breaking the connection between personal information and buying habit on amazon.com)
"0185fd1f5137ec04a564fdd8ef043e12fd643511" is 41 characters and there's no real way to reduce that. an int, even a large int ( oracle-style ) would come out to be neighborhood of 8 bytes, and thats being overly generous. those 33 bytes eventually add up, given indexes and other such things. additionally, most databases can compare ints faster than they can char(41) columns.
free cookie to the first person to point out why this person is on crack - if you don't do this sort of thing for a living, you get a larger cookie. :P