Re: [HACKERS] Proposal: GetOldestXminExtend for ignoring arbitraryvacuum flags

On 2017-02-15 12:27:11 -0500, Robert Haas wrote:
> On Tue, Feb 14, 2017 at 1:38 PM, Jim Nasby <Jim.Nasby@bluetreble.com> wrote:
> > On 2/14/17 3:13 AM, Seki, Eiji wrote:
> >>   +extern TransactionId GetOldestXmin(Relation rel, uint8 ignoreFlags);
> >
> >
> > My impression is that most other places that do this sort of thing just call
> > the argument 'flags', so as not to "lock in" a single idea of what the flags
> > are for. I can't readily think of another use for flags in GetOldestXmin,
> > but ISTM it's better to just go with "flags" instead of "ignoreFlags".
> 
> I agree; also, many years ago a guy named Tom Lane told me that flags
> argument should typically be declared as type "int".  I've followed
> that advice ever since.

Why is that?  I think uint makes a lot more sense for flags where the
flags are individual bits that set/unset. Doing that with the sign bit
isn't a good idea.

Andres