Date: Mon, 29 Oct 2018 16:02:18 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: "Joshua D. Drake" <jd@commandprompt.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: replication_slots usability issue
Message-ID: <20181029190218.uejy5cvgzygwrguy@alvherre.pgsql>
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On 2018-Oct-29, Joshua D. Drake wrote:

> -Hackers,
> 
> 
> Working on 9.6 today (unsure if fixed in newer versions). Had an issue where
> the wal was 280G despite max_wal_size being 8G. Found out there were stale
> replication slots from a recent base backup. I went to drop the replication
> slots and found that since the wal_level was set to minimal vs replica or
> higher, I couldn't drop the replication slot. Clearly that makes sense for
> creating a replication slot but it seems like an artificial limitation for
> dropping them.

This sounds closely related to
https://www.postgresql.org/message-id/20180508143725.mn3ivlyvgpul6ovr%40alvherre.pgsql
(commit a1f680d962ff) wherein we made it possible to drop a slot in
single-user mode.

Seems worth fixing.  Send a patch?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services