Re: Documentation Update: WAL & Checkpoints

Michael Renner wrote:
> Bruce Momjian wrote:
> > Michael Renner wrote:
> >> Hi,
> >>
> >> this is a small update to the first paragraph of the WAL configuration
> >> chapter, going into more detail WRT redo vs. checkpoint records, since
> >> the underlying behavior is currently only deducible from the source. I'm
> >> not perfectly sure if I got everything right, so feel free to change as
> >> necessary.
>
> [..]
>
> > I read over you patch and I was afraid it was trying to put too much
> > information into a single paragraph, so I added a second paragraph that
> > just talks about checkpoint smoothing. I did not address the issue of
> > when the REDO WAL entry is written --- that is probably too much detail
> > for our documentation.
>
> Too bad, understanding how this works is necessary to properly implement
> more complex log shipping setups. Maybe /backend/access/transam/README
> instead? Or specific "under the hood" paragraphs for selected areas of
> the DBMS?

Let's back up and let me ask why it is important for a user to know when
the REDO record is written vs. when the checkpoint completes, and how
that affects more complex log shipping setups.

This detail is certainly appropriate for /backend/access/transam/README
so if you could send in a patch, that would be great.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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