Subject: Re: PATCH: logical_work_mem and logical streaming of large
 in-progress transactions
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>,
 PostgreSQL Hackers <pgsql-hackers@postgresql.org>
References: <688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com>
 <bbe1333f-17ba-1156-0713-7cc0bfe2d842@2ndquadrant.com>
 <ca1e792e-6b59-bb9b-10ea-bf1d30c52548@2ndquadrant.com>
From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Organization: 2ndQuadrant
Message-ID: <dd03f188-d5f2-0089-0bf6-7d3abe4169ad@2ndquadrant.com>
Date: Mon, 8 Jan 2018 21:36:59 -0500
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On 1/3/18 15:13, Tomas Vondra wrote:
> Forgot to mention that the v4 also extends the CREATE SUBSCRIPTION to
> allow customizing the streaming and memory limit. So you can do
> 
>     CREATE SUBSCRIPTION ... WITH (streaming=on, work_mem=1024)
> 
> and this subscription will allow streaming, and the logica_work_mem (on
> provider) will be set to 1MB.

I was wondering already during PG10 development whether we should give
subscriptions a generic configuration array, like databases and roles
have, so we don't have to hardcode a bunch of similar stuff every time
we add an option like this.  At the time we only had synchronous_commit,
but now we're adding more.

Also, instead of sticking this into the START_REPLICATION command, could
we just run a SET command?  That should work over replication
connections as well.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services