Re: archive status ".ready" files may be created too early

On 2021-Aug-17, Bossart, Nathan wrote:

> On 8/16/21, 5:09 PM, "alvherre(at)alvh(dot)no-ip(dot)org" <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > The reason for the latter is that I suspect the segment boundary map
> > will also have a use to fix the streaming replication issue I mentioned
> > earlier in the thread. This also makes me think that we'll want the wal
> > record *start* address to be in the hash table too, not just its *end*
> > address. So we'll use the start-1 as position to send, rather than the
> > end-of-segment when GetFlushRecPtr() returns that.
>
> I've been thinking about the next steps for this one, too. ISTM we'll
> need to basically assume that the flush pointer jumps along record
> boundaries except for the cross-segment records. I don't know if that
> is the safest assumption, but I think the alternative involves
> recording every record boundary in the map.

I'm not sure I understand your idea correctly. Perhaps another solution
is to assume that the flush pointer jumps along record boundaries
*including* for cross-segment records. The problem stems precisely from
the fact that we set the flush pointer at segment boundaries, even when
they aren't record boundary.

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Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/
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