Re: Streaming replication and postmaster signaling

On Thu, Jan 7, 2010 at 21:22, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "Greg Sabino Mullane" <greg@turnstep.com> writes:
>>> However, HS is already in the tree, and HS without SR is a whole lot
>>> less compelling than HS with SR.  So it's going to be pretty
>>> unsatisfying if we can't get SR in there.
>
>> I don't think that's the case. Having HS alone would be a huge win,
>> and the sooner we can get it out there the better. Those that are
>> waiting for SR might have to wait one more version, but my intuition
>> tells me that's a small minority compared to those waiting for HS.
>
> No, I don't think so.  HS without SR means you still have to fool with
> setting up WAL-file-based replication, which despite the existence of
> pg_standby is a PITA.  And you have to make a tradeoff of how often to
> flush WAL files to the standby.  To be a real candidate for "it just
> works" replication, we've *got* to have SR.

Yes, but HS without SR certainly solves all the "need to offload my
reporting" kind of situations, which is still a very big thing. Yes,
it'll be much nicer with SR, but it will be *very* useful without it
as well.

-- Magnus HaganderMe: http://www.hagander.net/Work: http://www.redpill-linpro.com/