How to resolve unexpected ActiveRecord query performance degradation in Rails 7.1 when using custom scopes?
I'm working on a project and hit a roadblock. I'm experiencing significant performance issues when executing ActiveRecord queries with custom scopes in my Rails 7.1 application. Specifically, I have a scope defined on my `Post` model that filters posts based on a `published` status and a `created_at` date range. While the query works as expected for smaller datasets, it becomes increasingly slow with larger volumes of data. Here’s what my scope looks like: ```ruby class Post < ApplicationRecord scope :published_in_range, ->(start_date, end_date) { where(published: true).where(created_at: start_date..end_date) } end ``` When I run this query: ```ruby Post.published_in_range(1.month.ago, Time.current).load ``` I noticed that for larger datasets, it takes several seconds to complete. I’ve tried adding indexes on both the `published` and `created_at` columns, but that didn’t seem to have a noticeable impact. Additionally, I monitored the database logs and saw that the query being generated seems quite inefficient. Here's the SQL it generates: ```sql SELECT "posts".* FROM "posts" WHERE "posts"."published" = TRUE AND "posts"."created_at" BETWEEN '2023-09-01 00:00:00' AND '2023-10-01 00:00:00' ``` I’m unsure whether the issue lies with how the scope is being constructed or if it’s something to do with the underlying database (PostgreSQL). I also tried using `EXPLAIN ANALYZE` on the generated SQL, and it indicates a sequential scan instead of using the indexes. Any advice on how to optimize this query or diagnose further? Thanks in advance! For context: I'm using Ruby on Ubuntu. Is there a better approach?