Re: [PATCH 10/16] Introduce the concept that wal has a 'origin' node

On 20.06.2012 22:11, Simon Riggs wrote:
> On 21 June 2012 02:56, Simon Riggs<simon(at)2ndquadrant(dot)com> wrote:
>
>> I think allowing rmgrs to redefine the wasted bytes in the header is
>> the best idea.
>
> Hmm, I think the best idea is to save 2 bytes off the WAL header for
> all records, so there are no wasted bytes on 64bit or 32bit.
>
> That way the potential for use goes away and there's benefit for all,
> plus no argument about how to use those bytes in rarer cases.
>
> I'll work on that.

I don't think that's actually necessary, the WAL bloat isn't *that* bad
that we need to start shaving bytes from there. I was just trying to
make a point.

> And then we just put the originid on each heap record for MMR, in some
> manner, discussed later.

I reserve the right to object to that, too :-). Others raised the
concern that a 16-bit integer is not a very intuitive identifier. Also,
as discussed, for more complex scenarios just the originid is not
sufficient. ISTM that we need more flexibility.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com