Alexander Farber <alexander(dot)farber(at)gmail(dot)com> writes:
> I'm trying at the psql prompt of an UTF8 database in 8.4.13:
> # select '' ~ '^[\u0410-\u042F]{2,}$';
> WARNING: nonstandard use of escape in a string literal
I think Unicode escapes were introduced in 9.0. In 8.4 you'd probably
have to write out the UTF8 equivalent as octal escapes :-(
regards, tom lane