Help us test whether unlogged tables speed up your PostgreSQL test suite

[mgibowski]

Hi, if you have a test suite with many DB tests that use PostgreSQL, we would like to hear about the impact on suite execution with this feature.

I’m curious to hear from folks about the impact and whether it’s worth adding such a feature at all.

If you want to try it on your codebase, follow these steps:

1. Update your dependencies to:

{:ecto_sql, git: "https://github.com/mgibowski/ecto_sql.git", branch: "unlogged", override: true}, {:ecto, git: "https://github.com/elixir-ecto/ecto.git", override: true},

2. In the test.exs file, add the following configuration:

config :your_app, YourApp.Repo, create_unlogged_tables: true

3. And reset your database in the test environment:

MIX_ENV=test mix ecto.reset

Details here: Experiment: Support for creating unlogged tables to speed up tests by mgibowski · Pull Request #601 · elixir-ecto/ecto_sql · GitHub

[LostKobrakai]

This came up a few weeks back on twitter, but initial experiments didn‘t seems to provide any tangible speedups. I would expect that‘s because with the ecto sandbox most writes are never committed in the first place with ecto.

[mgibowski]

Somebody reported some good results:
https://x.com/nelsonmestevao/status/1741097876564984299?s=20
I tried using unlogged tables some time ago on a project I no longer have access to. It had around 400 tests, and the improvement was about 10% / 1.5 seconds.
I tried that branch yesterday on changelog.org and the hexpm codebases, and I cannot tell there is any improvement. Test execution times are sometimes faster and sometimes slower.

[LostKobrakai]

@mgibowski

Test execution times are sometimes faster and sometimes slower.

I ran it at the time on a ~900 tests project of mine and had similar results.