Getting environment variables?

All-

I'd like to be able to create a view like this:

create view my_view as select * from real_table where check_cred(row.id)

where check_cred(row.id) is a function that checks for some externally
available credential or 'ticket' and only shows the rows in the table
that the id is allowed to see. Basically, I want to create 'virtual
users' inside of my database without creating a separate view for each
user. My problem is getting check_cred() to see the 'ticket' without
having it passed in with the query.

Environment variables won't workas the backend executes the query,
and doesn't have my environment. Some client/server thing would work,
I suppose, but I don't really want to code one if it can be avoided.
Is there an easier solution?

Also, is there a repository for user-created postgresql
types/functions anywhere? Some of the things I'm doing have to have
been done already, and done better.

Thanks,

-mike

--

And though the holes were rather small
They had to count them all
Now they know how many holes it takes to fill the Albert Hall
*I'd love to turn you on*

-- Beatles, "A Day in the Life"

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