Re: Review for GetWALAvailability()

On 2020-Jun-25, Kyotaro Horiguchi wrote:

> It is error-prone restriction, as discussed before.
> 
> Without changing updator-side, invalid restart_lsn AND valid
> invalidated_at can be regarded as the lost state. With the following
> change suggested by Fujii-san we can avoid the confusing status.
> 
> With attached first patch on top of the slot-dirtify fix below, we get
> "lost" for invalidated slots after restart.

Makes sense.  I pushed this change, thanks.


> The confusing status can be avoided without fixing it, but I prefer to
> fix it.  As Fujii-san suggested upthread, couldn't we remember
> lastRemovedSegNo in the contorl file? (Yeah, it cuases a bump of
> PG_CONTROL_VERSION and CATALOG_VERSION_NO?).

I think that's a pg14 change.  Feel free to submit a patch to the
commitfest.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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