Re: 'Session local' variables

"Nick Johnson" <arachnid@notdot.net> writes:
> On 7/2/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> "Nick Johnson" <arachnid@notdot.net> writes:
>>> I want to write a contrib module that exports a couple of functions
>>> that PLs (that don't natively support this) can use to set/get
>>> session-local variables.
>>
>> Um, why do you need to do anything?  Don't current_setting() and
>> set_config() cover this?

> I thought those were supposed to be reserved for postgres's
> configuration options?

Oh, you meant arbitrary new variables.  You can (ab)use
custom_variable_classes for that.  I've also seen people do it
with plperl or pltcl, using those languages' inbuilt capacity
for process-lifetime variables.  (Probably plpython can do it
too, but I'm mostly clueless wrt python.)

Anyway, there are multiple ways to do this with just a couple
lines of code, so I don't see a need for a contrib module.

            regards, tom lane