I'm seeing a very inconsistent performance profile...

# squarelibraries

[eygraber]

I'm seeing a very inconsistent performance profile for verifyMigration on CI. Locally it completes very consistently, but when running on CI I see times ranging from 2m30s going up to 9m.

I tried using a GitHub Actions large runner for that task (32 cores, using an Xmx of 32g) and while it seems to have stabilized (albeit with a very small sample size), I'm surprised that it didn't have an effect on how long it takes to execute (4m30s). I'm guessing it's not very parallelizable but I would've thought that the bump in CPU power and RAM would make it complete faster.

I'm not running into the issue with having multiple db files (I only have 1). Any thoughts or ideas on how I could speed things up?

[jessewilson]

RAM disk. Use the tmpfs config here:
https://www.baeldung.com/linux/files-ram

[eygraber]

Thanks, that shaved 30-40% off of the execution time!

[Marcelo Gobetti]

to me, tmpfs helped speed it up, but the inconsistency and longer times had Java 21 as the main culprit by far https://github.com/cashapp/sqldelight/issues/4759#issuecomment-1922239276