temporal_tables VS simonwillisonblog-backup

It was reimplemented in pure SQL here https://github.com/nearform/temporal_tables for this purpose

I enjoyed this blog. I think it provides a great succinct overview of various approaches native to Postgres.

For the "capture changes in an audit table" section, I've had good experiences at a previous company with the Temporal Tables pattern. Unlike other major RDBMS vendors, it's not built into Postgres itself, but there's a simple pattern [1] you can leverage with a SQL function.

This allows you to see a table's state as of a specific point in time. Some sample use cases:

- "What was this user's configuration on Aug 12?"

- "How many records were unprocessed at 11:55pm last night?"

- "Show me the diff on feature flags between now and a week ago"

[1]: https://github.com/nearform/temporal_tables

One of these Postgres-based implementations of SQL:2011's temporal versioning features might get you close enough:

- https://github.com/nearform/temporal_tables

You don't really need to install an extension to use temporal tables, there is an alternative (https://github.com/nearform/temporal_tables) implemented purely as a plpgsql trigger so that it works everywhere.

I was part of a team at NearForm using this for a project on an EC2 instance. In order to move to AWS RDS we had to recreate the functionality of temporal_tables as a PostgreSQL function, rather than extension.

When we switched, we found that although there were minor bugs, we didn't have any noticeable loss of performance and we have used it ever since for many projects.

https://github.com/nearform/temporal_tables

If you're also limited by cloud services and the extensions limitations, this is a great solution.

> I’ve been running that for a couple of years in this repo: https://github.com/simonw/simonwillisonblog-backup - which provides a backup of my blog’s PostgreSQL Django database (first converted to SQLite and then dumped out using sqlite-

I'm curious, what is the reason you chose not to use pgdump, but instead opted to convert to to sqlite and then dump the DB using sqlite-diffable?

On a project I'm working on, I'd like to dump our Postgres schema into individual files for each object (i.e., one file for each table, function, stored proc, etc.), but haven't spent enough time to see if pgdump could actually do that. We're just outputting files by object type for now (one tables, function, and stored procs files).

My personal blog runs on Django + PostgreSQL, and I got fed up of not having a version history of changes I made to my content there.

I solved that by setting up a GitHub repo that mirrors the content from my database to flat files a few times a day and commits any changes.

It's worked out really well so far. It wasn't much trouble to setup and it's now been running for nearly three years, capturing 1400+ changes.

I'd absolutely consider using the same technique for a commercial project in the future:

Latest commits are here: https://github.com/simonw/simonwillisonblog-backup/commits/m...

Workflow is https://github.com/simonw/simonwillisonblog-backup/blob/main...

If you really, really need to be able to see a SQL schema representing the current state, a cheap trick is to run an automation on every deploy that snapshots the schema and writes it to a GitHub repository.

I do a version of that for my own (Django-powered) blog here: https://github.com/simonw/simonwillisonblog-backup/blob/main...

My blog is Django and PostgreSQL on Heroku, but last year I decided I wanted a reliable long-term public backup... so I set up a scheduled GitHub Actions workflow to back it up to a git repository.

Bonus feature: since it runs nightly it gives me diffs if changes I make to my content, including edits to old posts.

The backups are in this repo: https://github.com/simonw/simonwillisonblog-backup