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by snowwolf 3553 days ago
Please can the Postgres team put some major focus on completing logical replication [1]. It's the missing piece to making upgrading across major versions painless and quick on large databases so that we can take advantage of all these nice new features. We're on a Heroku's hosted Postgres service so can't install the pglogical extension.

1. http://blog.2ndquadrant.com/why-logical-replication/
2 comments
rpedela 3553 days ago
It is being worked on. There is a good chance it will be in the next major version.

https://commitfest.postgresql.org/10/701/

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mslate 3553 days ago
I don't think you would be able to take advantage of logical replication on Heroku Postgres regardless--they don't allow you to replicate to your own instances, only other Heroku-hosted instances.

This makes migrating off Heroku for Postgres a PITA and requiring down-time.

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snowwolf 3553 days ago
True, that would be an extra bonus if Heroku started allowing replication to non Heroku instances, but as long as they support logical replication to a Heroku Follower instance then you can upgrade to new major versions with near zero downtime - set up logical follower running latest postgres version and then promote to master once it has caught up. Currently you can't have a follower that is a different version to master - meaning an upgrade requires either a full backup and restore to new version resulting in significant downtime if you have a large database or using the pg_upgrade utility which is generally not recommended as it is not guaranteed to work.
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