RFC: get_record_stream and groupcompress

[Andrew Bennetts]

Robert Collins wrote:
> So I've a thorny little tradeoff to encapsulate in code.
> 
> The best approach I've thought of to date is a parameter to
> VF.get_record_stream called 'sort_is_hint'. If you think that that
> sounds fine and dandy, say so now and skip the detail below.

Given what you say below, I think this ok.  Giving more information to
the callee about what's required vs. what's merely desirable for the
caller makes sense to me.

-Andrew.