Performance Bottlenecks in CI/CD Pipeline with ActiveRecord Queries in Rails 7
I'm converting an old project and Currently developing a Rails application that integrates tightly with our CI/CD pipeline, I've noticed some performance issues that are becoming increasingly problematic. Particularly, during deployment, the ActiveRecord queries seem to be the bottleneck. After profiling the application using `rack-mini-profiler`, it became clear that certain queries are taking significantly longer than expected. For example, a simple retrieval of user records using: ```ruby User.where(active: true).includes(:profile).order(:created_at) ``` is taking over 300ms in production. In my local environment, this runs efficiently, clocking in under 50ms. I've tried adding indexes to the `active` and `created_at` columns, yet the performance hasn't improved much. Further investigation into the production logs revealed that when this query is executed multiple times (for instance, when displaying user data on the dashboard), it compounds the issue. To mitigate this, I implemented caching using Rails' built-in fragment caching, but it only alleviated the problem moderately. The cache hit rate isn't great, as the data is frequently updated. Additionally, I've been exploring the use of `bullet` gem to identify N+1 queries in the application. Running it in development mode has pointed out several areas for optimization, but I'm concerned about the implications on the CI/CD process with many developers contributing concurrently. Could anyone suggest more advanced strategies for optimizing ActiveRecord queries in a CI/CD context? What other tools or techniques can help ensure that our deployment times do not escalate due to these database interactions? Any insights into this would be greatly appreciated. Any pointers in the right direction?