[Bug] Sideload Allowlist causes n+1 queries

[Reizar]

Hi,

We've been getting hit hard with n+1 queries in our codebase and its been causing quite a few issues. We do a lot of nested includes in our models but I thought Graphiti was supposed to handle loading them without n+1 queries.

I set up a new codebase and mirrored some of our models/associations to see if I could work out what the cause of the issue is. And I've found that when the sideload_allowlist is used, the n+1 queries happen. When I remove it, eager loading is used correctly.

Please see this codebase: https://github.com/Reizar/graphiti-nplus1-example for a reproduction of the issue.

Steps to reproduce:

1. Clone codebase linked above.
2. Run rails db:migrate
3. Run rails db:seed
4. Run rails server -p 5000
5. Visit: http://127.0.0.1:5000/api/v1/inspections?include=tenancy.tenancy_memberships.user,tenancy.property&page[number]=1&page[size]=100

You should see the rails console filled with tonnes of DB queries.

Then:

1. Open up app/controllers/inspections_controller.rb
2. Comment out the self.sideload_allowlist = code
3. Visit the url above again
4. The queries should be reduced down to just the number of associations.

Feels like this is probably a bug, but it could also be an issue on our side of how we're using the sideload allowlist. Happy to hear any thoughts or provide additional information.

[jkeen]

@Reizar I don't think graphiti does anything super magical to avoid N+1 queries. When I've run into N+1s they've been solved by changing my base_scope in my resource to use Rails eager loading.

Thank you for setting up the example repo! When I looked at it briefly it seemed like you were getting N+1s on loading the user record with or without the sideload allow list, but I didn't look at it deep enough to fully understand your domain model and what .includes or .eager_loads you'd need to add to avoid that N+1. Have you tried modifying your base_scopes?