Re: Regardign RecentFlushPtr in WalSndWaitForWal()

Hi,

On Mon, Feb 26, 2024 at 05:16:39PM +0530, shveta malik wrote:
> Hi hackers,
>
> I would like to understand why we have code [1] that retrieves
> RecentFlushPtr in WalSndWaitForWal() outside of the loop. We utilize
> RecentFlushPtr later within the loop, but prior to that, we already
> have [2]. Wouldn't [2] alone be sufficient?
>
> Just to check the impact, I ran 'make check-world' after removing [1],
> and did not see any issue exposed by the test at-least.
>
> Any thoughts?
>
> [1]:
> /* Get a more recent flush pointer. */
> if (!RecoveryInProgress())
> RecentFlushPtr = GetFlushRecPtr(NULL);
> else
> RecentFlushPtr = GetXLogReplayRecPtr(NULL);
>
> [2]:
> /* Update our idea of the currently flushed position. */
> else if (!RecoveryInProgress())
> RecentFlushPtr = GetFlushRecPtr(NULL);
> else
> RecentFlushPtr = GetXLogReplayRecPtr(NULL);
>

It seems to me that [2] alone could be sufficient.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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