Using different types/format of _id ok?

I'm using one database for all (users, files and comments).

I was wondering if I can/should use

• twitter user id for user doc _id's
• md5 hash (of file) fo开发者_Go百科r file doc _id's
• provided uuid for comment doc _id's

It feels weird to mix those different types of id's.

What speaks agains this scenario? Should I stick to the CouchDB uuid's for consistency?

Use any format of id, or combination of formats, as you see fit. You might wish to add a prefix to ensure there are no overlaps between them, though.

twitter:@rnewson
md5:86f646c11b3bc7d434d06c077aee43d8

And so on.