Why AO3 Was Down

> typical database column

Typical for 70s and 80s.

Honestly, designing a 21st century database is a different thing if compared to back then.

You can use 128 bit integers, provided that you really want to use integers. And maybe you put a timestamp along.

let's use 128bit integer and handle them like floats in php!

and maybe put a 32bit timestamp along and pretend it can somehow store more than a 32bit integer can.

or use UUID/GUIDS, many databases (eg PostgreSQL) and frameworks (eg Django) support them.

Using uuids can cause lots of problems with indexing, fragmentation, row size and index size

Nah I made the same mistake back in 2009 for a system that was storing behavior events during malware analysis.

You don’t often expect to have two billion of something until you do.

It's not like those two billion things just materialise in your database, right? Someone must have watched that graph climb, and climb, and climb, approaching the limit.

Salesforce is a rather popular platform.

Its defaults are also either a 18-character ID, or a 32bit integer. So, unless you take the effort to actually fight Apex, you're gonna hit this problem sooner or later.

If they have that graph and remember the limit they choose 15 years ago... It's not something you think about constantly running a mostly stable code-wise site.

One of the first things I internalized about databases was "just always use BIGSERIAL for primary keys". There are very few good reasons not to.

The website appears to date from 2008. This was a _very_ common latent bug at that point, particularly because Rails would basically force you to implement it. I assume this got fixed at some point, but for a long time all ActiveRecord models had an autoincrementing ID, which had to be a signed 32 bit int. There were scary monkey-patching workarounds if you wanted something more sensible.

EDIT: And, yes, it is apparently Rails! https://fanlore.org/wiki/Archive_of_Our_Own#Timeline

Maybe don't: https://wiki.postgresql.org/wiki/Don't_Do_This#Don.27t_use_s...

Doesn’t an 18-character alphanumeric ID give you 18^36 combinations? 1.54 x 10^45 seems like enough combinations.

That's the point of the "or". You probably don't know which you're getting. It's what makes that particular design decision bite you more often.