Newest release breaks compatibility with PostgreSQL 9.4

[raucao]

We're on an older LTS of Ubuntu, which only gets 9.4 by default. Until v2.5.0 it worked without problems, but the migrations for the latest release include one with an upsert statement, which is only available in postgres 9.5 and newer:

https://github.com/tootsuite/mastodon/blob/master/db/migrate/20180812173710_copy_status_stats.rb#L12-L13

I looked into upgrading postgres on this server, but it would be too difficult with our current setup. Would be great if this migration could be refactored to also work on 9.4, because everything else in Mastodon seems to be compatible.

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• I searched or browsed the repo’s other issues to ensure this is not a duplicate.
• This bug happens on a tagged release and not on master (If you're a user, don't worry about this).

[JMendyk]

ON CONFLICT syntax for INSERT was added in version 9.5 (see: INSERT in versions 9.4 and 9.5).

[Laurelai]

Also affected by this issue

[joachimesque]

Also affected by the issue.

[nemsia]

Also affected by the issue on Debian jessie

[abochmann]

As for Debian, postgresql 9.6 is in jessie-backports: https://packages.debian.org/jessie-backports/postgresql
See https://backports.debian.org/Instructions/#index2h2 on how to add that to your sources. I think upgrading Postgres requires some manual intervention, but the relevant notes should be included.

[Laurelai]

Any advice for centos 7

[saper]

@Laurelai For CentOS and other RedHat derivatives PGDG (PostgreSQL Development Group) publishes very good RPMs, but migrating to use them may not be straightforward.

[Laurelai]

Its sure not, i tried today, did so now my timelines are gone ^_^

[Gargron]

Could you please tell me if #8903 solves your issue sufficiently?