Re: Hot Backup with rsync fails at pg_clog if under load

On Thu, Oct 27, 2011 at 4:36 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Wed, Oct 26, 2011 at 12:16 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>>> This fixes both the subtrans and clog bugs in one patch.
>
>> I don't see the point of changing StartupCLOG() to be an empty
>> function and adding a new function TrimCLOG() that does everything
>> StartupCLOG() used to do.
>
> +1 ... I found that overly cute also.

It would have been even easier to move StartupCLOG() later, but then
we'd need a big comment explaining why CLOG starts up at one point and
subtrans starts up at another point, since that is very confusing way
of doing things. I wrote it that way first and it definitely looks
strange.

It's much easier to understand that StartupCLOG() is actually a no-op
and that we need to trim the clog at the end of recovery in all cases.

The patch isn't meant to be cute, just a better of way of expressing
what needs to be done, so I think the patch should stay that way.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
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