> I can't see a reason why we would use a new WAL record for this,
> rather than modify the XLOG_PARAMETER_CHANGE record type which was
> created for a very similar reason.
> The code would be much simpler if we just extend
> XLOG_PARAMETER_CHANGE, so please can we do that?
Sure.
> The log message "full_page_writes on master is set invalid more than
> once during online backup" should read "at least once" rather than
> "more than once".
Yes.
> lastFpwDisabledLSN needs to be initialized.
I think it don't need because all values in XLogCtl is initialized 0.
> Is there a reason to add lastFpwDisabledLSN onto the Control file? If
> we log parameters after every checkpoint then we'll know the values
> when we startup. If we keep logging parameters this way we'll end up
> with a very awkward and large control file. I would personally prefer
> to avoid that, but that thought could go either way. Let's see if
> anyone else thinks that also.
Yes. I add to CreateCheckPoint().
Image: CreateCheckPoint() { if (!shutdown && XLogStandbyInfoActive()) { LogStandbySnapshot()
XLogReportParameters() } }
XLogReportParameters() { if (fpw == 'off' || ... ) XLOGINSERT() }
However, it'll write XLOG_PARAMETER_CHANGE every checkpoints when FPW is 'off'.
(It will increases the amount of WAL.)
Is it OK?
Regards.
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Jun Ishizuka
NTT Software Corporation
TEL：045-317-7018
E-Mail: ishizuka.jun@po.ntts.co.jp
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