[branko_d]

> Boolean is rarely enough for real production workloads. You need a 'processing' ... 'retrying'... 'failed' ...

If you have more than 2 states, then just use integer instead or boolean.

> Saving a few bytes on the index isn't worth losing that observability.

Not sure why having a few well-known string values is more "observable" than having a few well-known integer values.

Also, it might be worth having better write performance. When PostgreSQL updates a row, it actually creates a new physical row version (for MVCC), so the less it has to copy the better.

[throw_away_623]

Postgres supports enum that would fit this use case well. You get the readability of text and the storage efficiency of an integer. Adding new values used to require a bit of work, but version 9.1 introduced support for it.