Re: "using previous checkpoint record at" maybe not the greatest idea?

On 2/4/16 5:09 PM, David G. Johnston wrote:
>
> What the 2nd para in the documentation is saying is something different:
> it is talking about reading all the pg_xlog files (in reverse order),
> which is not pg_control, and see what checkpoint records are there, then
> figure out which one to use.
>
>
> Yes, I inferred something that obviously isn't true - that the system
> doesn't go hunting for a valid checkpoint to begin recovery from. While
> it does not do so in the case of a corrupted pg_control file I further
> assumed it never did. That would be because the documentation doesn't
> make the point of stating that two checkpoint positions exist and that
> PostgreSQL will try the second one if the first one proves unusable.
> Given the topic of this thread that omission makes the documentation
> out-of-date. Maybe its covered elsewhere but since this section
> addresses locating a starting point I would expect any such description
> ​to be here as well.

Yeah, I think we should fix the docs. Especially since I imagine that if
you're reading that part of the docs you're probably having a really bad
day, and bad info won't help you...
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com