[gregwebs]

I think switching this with zero downtime to do foreign key references with UUIDs will be easier than any of the pain you would deal with from having to do cross-DB joins.

What specific issues are you worried about with the integer key? Usually the issue is dupming data into something like a staging or development environment rather than a production concern. If you attempt to dump 2 datasets into one db you will have a conflict. Or if you write to an environment and then dump into you will have a conflict.

[babbledabbler]

Mainly portability of data and options for the future. I'm all on one postgres instance right now and don't plan on breaking it up until necessary. If at some point I need to take a table and move it to another type of database I want that migration process to be straightforward. If I have integer keys with sequencing behavior I anticipate having to do that porting. That internal key would then become external to do the lookup and if it's an external key I want it to be UUID for security as well. Integers as IDs are guessable so I want to keep them internal.