Re: Optional postgres database not so optional in 8.1

Tom Lane wrote:

>Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
>
>
>>I now notice that "pg_ctl -w start" fails if the postgres db is missing.
>>I am not sure that changing pg_ctl to use this rather than template1 was
>>a good thing, and it can't be overridden. I suggest we revert that
>>particular change - it seems to me to confer little to no benefit,
>>unlike the case with createdb etc.
>>
>>
>
>pg_ctl -w is already incredibly fragile because it needs a working
>password-free login name. Rather than worrying about whether the
>database name exists, what we ought to do is invent the long-awaited
>"ping" extension to the postmaster protocol --- something that would
>just ask "are you up and ready to accept connections" without having
>to specify a valid user *or* database name.
>
>You can sort of do this today if you are willing to examine the error
>message that comes back from the postmaster, but I think it'd be cleaner
>to have an official protocol extension.
>
>

Actually, it looks like pg_ctl already does this:

if ((conn = PQsetdbLogin(NULL, portstr, NULL, NULL,
"postgres", NULL, NULL)) != NULL &&
(PQstatus(conn) == CONNECTION_OK ||
(strcmp(PQerrorMessage(conn),
PQnoPasswordSupplied) == 0)))
{
PQfinish(conn);
success = true;
break;
}

cheers

andrew