Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1ehXEl-0007IF-60 for pgsql-hackers@arkaria.postgresql.org; Fri, 02 Feb 2018 09:02:23 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ehXEk-0001zK-88 for pgsql-hackers@arkaria.postgresql.org; Fri, 02 Feb 2018 09:02:22 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1ehXEj-0001zA-U4 for pgsql-hackers@lists.postgresql.org; Fri, 02 Feb 2018 09:02:22 +0000 Received: from tamriel.snowman.net ([96.255.250.162]) by makus.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1ehXET-0000Cz-TA for pgsql-hackers@postgresql.org; Fri, 02 Feb 2018 09:02:20 +0000 Received: by tamriel.snowman.net (Postfix, from userid 1000) id 8A6B75F79C; Fri, 2 Feb 2018 04:02:04 -0500 (EST) Date: Fri, 2 Feb 2018 04:02:04 -0500 From: Stephen Frost To: Simon Riggs Cc: Ivan Kartyshov , PostgreSQL-development Subject: Re: [HACKERS] make async slave to wait for lsn to be replayed Message-ID: <20180202090204.GQ2416@tamriel.snowman.net> References: <0240c26c-9f84-30ea-fca9-93ab2df5f305@postgrespro.ru> <20180122232100.GZ2416@tamriel.snowman.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="t1jiH6IM2fE5/QhK" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk --t1jiH6IM2fE5/QhK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Greetings, * Simon Riggs (simon@2ndquadrant.com) wrote: > On 22 January 2018 at 23:21, Stephen Frost wrote: >=20 > >> It sounds reasonable. I can offer the following version. > >> > >> WAIT LSN lsn_number; > >> WAIT LSN lsn_number TIMEOUT delay; > >> WAIT LSN lsn_number INFINITE; > >> WAIT LSN lsn_number NOWAIT; > >> > >> > >> WAIT [token] wait_value [option]; > >> > >> token - [LSN, TIME | TIMESTAMP | CSN | XID] > >> option - [TIMEOUT | INFINITE | NOWAIT] > >> > >> Ready to listen to your suggestions. > > > > There were a few different suggestions made, but somehow this thread > > ended up in Needs Review again while still having LSNs. I've changed it > > back to Waiting for Author since it seems pretty unlikely that using LSN > > is going to be acceptable based on the feedback. >=20 > I agree with the need for a separate command rather than a function. >=20 > I agree that WAIT LSN is good syntax because this allows us to wait > for something else in future. >=20 > Without having reviewed the patch, I think we want this feature in PG11. I've also looked back through this and while I understand the up-thread discussion about having something better than LSN, I don't see any particular reason to not allow waiting on LSN, so I agree with Simon that this makes sense to include. There are definite cases it helps with today and it doesn't block off future work. As we're closing out the January commitfest, I've moved this to the next one. Thanks! Stephen --t1jiH6IM2fE5/QhK Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCgAGBQJadCkMAAoJEO1sijiDR2RVffkP/0fzqvJJLXn/2yV4a+taTNCB sjd1AYwHVXQ7+vjtXHMV5mUdGXciTDIqKND0O5LrLON3mIW8pKYny5lUXcIT62x4 jbW7MWzSVf1xIs8v5rUihsZsi5pMTVtWXu2x+kxlT9U3NQWVq8x5QqYO9TKeslD3 Rqu4mifPMD6lh7UMrANLlASvEvv4SOTx+yc27TUWMf8fguRDXynYNC6AGw+PfT50 ph9DlQQHNB8duo5O5XewNG4B1wBexdRKld2qALDiv03Kw91iYtR/FWXj7UrX/FGl cefIrueExHetayIpC7Qw4zBr8RTNku/Jw+0bq8zYOJOPev70LzxRANyssrIZ9Sdl 93TpGWxOi4oatslOqvKGdUdbOVMzu1Y/cIrS3oXsihi/9btmD3ct1CPNYLXyowlS vIPqxB9MLGAZN9irQgUtZq85LRG3xM0eM+hFGs6QD8ki4dPAXxhrRmEwDxUb2bpO GbJODeBNbOPeyggMf11fa3bs2L6eh+QFUvmpUAk7XVamN4hjIhogOO9FULxXoeQo fKKm3NgTnwvpvGzNn2JCo0MYi7HCQ91ebf4l7K7j+dZZj5Y0tEML/Gc8jJDNf9My vZacDvM9ntu+QRpSXbBvRJgIW31Ez3c41VjQt0NnPo/dShmFlAEfKGUfFmen0baa d2SBcwmuW2AwOSVJ1U27 =CP96 -----END PGP SIGNATURE----- --t1jiH6IM2fE5/QhK--