Graeme B. Bell schrieb am 09.07.2015 um 11:44:
> I don't recall seeing a clear statement telling me I should mark pl/pgsql
> functions nonvolatile wherever possible or throw all performance and
> scalability out the window.
From: http://www.postgresql.org/docs/current/static/xfunc-volatility.html
"For best optimization results, you should label your functions
with the strictest volatility category that is valid for them."