Similar question has been asked many times on mailing lists and on IRC. Sometimes it's not mail sending, but file/directory creation, or something else that generally requires some interaction with "world outside of database". Can it be done? Sure. How, then?

On 8th of February, Peter Eisentraut committed patch: Per-column collation support   This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support.   Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch   Branch ------ master

I have an unusual mail setup. My company mails are handled by gmail, and on my account there, I setup forwarding to my own mail account on my own server. Where I read the mails, and respond. So, when someone (let's say ...

On 29th of July, Tom Lane committed patch written by David E. Wheeler, which added new contrib module: citext.