From: Ronan Dunklau <ronan.dunklau@aiven.io>
To: Michael Paquier <michael@paquier.xyz>
Cc: pgsql-hackers@lists.postgresql.org,
 Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>,
 Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
 Masahiko Sawada <sawada.mshk@gmail.com>
Subject: Re: pg_receivewal starting position
Date: Mon, 25 Oct 2021 09:50:01 +0200
Message-ID: <3162614.44csPzL39Z@aivenronan>
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Le lundi 25 octobre 2021, 09:40:10 CEST Michael Paquier a =E9crit :
> On Mon, Oct 25, 2021 at 09:15:32AM +0200, Ronan Dunklau wrote:
> > Does it make sense though ? The NULL slot_name case handling is pretty
> > straight forward has it will be handled by string formatting, but in the
> > case of a null restart_lsn, we have no way of knowing if the command was
> > issued at all.
>=20
> If I am following your point, I don't think that it matters much here,
> and it seems useful to me to be able to pass NULL for both of them, so
> as one can check if the slot exists or not with an API designed this
> way.

You're right, but I'm afraid we would have to check the server version twic=
e=20
in any case different from the basic pg_receivewal on (once in the function=
=20
itself, and one before calling it if we want a meaningful result). Maybe we=
=20
should move the version check outside the GetSlotInformation function to av=
oid=20
this, and let it fail with a syntax error when the server doesn't support i=
t ?

=2D-=20
Ronan Dunklau