scenarios when using `find_each` with large datasets in Rails 7 - Unexpected `nil` results
I'm writing unit tests and I'm maintaining legacy code that I'm working on a Rails 7 application where I need to process a large dataset efficiently. I'm using the `find_each` method on an ActiveRecord model to iterate through records in batches. However, I'm working with an scenario where some of the records return `nil` unexpectedly during iteration. Here's a simplified version of my code: ```ruby User.find_each(batch_size: 1000) do |user| next if user.nil? # This check is not helping # Performing some operation on user puts user.name end ``` I have checked the database and confirmed that there are no deleted or nil records in the User table. The strange part is that when I use `all.each` instead, everything works fine: ```ruby User.all.each do |user| puts user.name end ``` This does not return any nil values. I suspect it might be related to how `find_each` loads the records in batches, but I've tried debugging by adding logging and it seems like records are being loaded correctly at first. I also verified that `find_each` is querying the database effectively by checking the SQL logs, which show that it fetches 1000 records at a time without issues. To further investigate, I added some logging: ```ruby User.find_each(batch_size: 1000) do |user| puts "Processing user: #{user.inspect}" end ``` This logging shows that some users do appear as `nil`. Has anyone else experienced this behavior? Are there any known issues with `find_each` in Rails 7, or could there be something wrong with my setup? Any guidance would be greatly appreciated. My development environment is Linux. For reference, this is a production web app. Cheers for any assistance!