Re: [development] Best place to store user data

So let me add a bit to the question because I just came across it in a contrib. Let's say you need one field that exactly matches a core table. Is it ever okay, upgrades aside, to add that column to the core table? Some things I've read about D7 seem to indicate this will be okay in D7. The use of "drupal_write_record" really makes this a convenient practice.

Depends on who you ask. My position is that adding a column to a foreign table is OK if the code will not be shared. IOW, custom code for your own site. It is especially OK for the user table since it has built in support for custom columns. I discourage this practice for Contrib modules since the users of the module are usually unprepared to evaluate the upgrade risks involved.