Re: WAL format and API changes (9.5)

On Thu, Aug 14, 2014 at 3:04 AM, Alvaro Herrera
<alvherre(at)2ndquadrant(dot)com> wrote:
> Heikki Linnakangas wrote:
> What's with XLogReplayLSN and XLogReplayRecord? IMO the xlog code has
> more than enough global variables already, it'd be good to avoid two
> more if possible. Is there no other good way to get this info down to
> whatever it is that needs them?
Yep, they do not look necessary. Looking at the patch, you could get
rid of XLogReplayLSN and XLogReplayRecord by adding two extra argument
to XLogReplayBuffer: one for the LSN of the current record, and a
second for the record pointer. The code just saves those two variables
in the redo loop of StartupXLOG to only reuse them in
XLogReplayBufferExtended, and I saw no code paths in the redo routines
where XLogReplayBuffer is called at places without the LSN position
and the record pointer.

However I think that Heikki introduced those two variables to make the
move to the next patch easier.
Regards,
--
Michael