Question about case-insensitive columns in Rails

My question.txt

Hola Rails people. I have a column in my database that I need to treat
as case-insensitive. The standard solution to this is to downcase the
value before inserting it into the database, and when doing
searches. My problems with this are:

1. I have to make calls to String#downcase in several places where I
*really* mean "this is case-insensitive"

2. I can only provide automatic-downcasing when going through the API
I provide. Anyone calling MyClass.where(:name => foo) has to know to
pass in a downcased version of foo.

I can think a few possible solution areas off the top of my head:

1. Do everything in the database. How exactly? Maybe I can create a
virtual column or view, and have a trigger on the db. DBMS is
Postgres, whatever version Heroku runs :)

2. A gem or plugin that treats entire columns as case-insentive by
automatically downcasing stuff as well as hooking into any arbitrary
SQL queries and dowcasing them.

3. Something much simpler that I haven't thought of :)

What do you guys know?

I'll accept that as praise