Re: point in time recovery and moving datafiles online

Zeugswetter Andreas SB SD wrote:
> > > Yes. But I think you might have to avoid "vacuum full" during data file backup.
> > 
> > Why?  If vacuum is unsafe in this scenario, wouldn't it also be unsafe
> > in event of a system crash?
> 
> I was not sure we are 100% crash safe during "vacuum full".
> But yes, now recalling your last remark on a crash during vacuum full
> I guess we should be.
> 
> > I do believe that vacuum should (but presently does not) emit a WAL
> > record showing its truncation of the file, so that the equivalent
> > truncation can be repeated during replay.
> 
> > However, this is needed in any case.
> 
> I see, but it has only the effect of not freeing the space to the OS, 
> so it is not really a bug ? Next vacuum will do it anyway. 

One idea is that replication can give is point-in-time recovery.  A
recovery is nothing more than a replication slave taking the last full
backup and reading the replication traffic to get itself up to date.

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