Poor performance of '/api/events'

[Daniel Axtens]

Stephen Finucane <stephen at that.guru> writes:

> I've noticed some poor performance for 'patchwork.ozlabs.org/api/events' when
> accessed via a browser or fetched via cURL. I haven't seen similar issues on
> any other endpoint and I also can't see anything funky going on with regards to
> number of database queries for this endpoint when running Patchwork locally.
>
> Has anyone else seen this issue? I'm away for the next two weeks but if someone
> has a chance to look at this in the interim I'd be very appreciative.

Wheeee that does a *massive* database query:
	
SELECT ... FROM "patchwork_event" INNER JOIN "patchwork_project" ON ("patchwork_event"."project_id" = "patchwork_project"."id") LEFT OUTER JOIN "patchwork_patch" ON ("patchwork_event"."patch_id" = "patchwork_patch"."submission_ptr_id") LEFT OUTER JOIN "patchwork_submission" ON ("patchwork_patch"."submission_ptr_id" = "patchwork_submission"."id") LEFT OUTER JOIN "patchwork_series" ON ("patchwork_event"."series_id" = "patchwork_series"."id") LEFT OUTER JOIN "patchwork_coverletter" ON ("patchwork_event"."cover_id" = "patchwork_coverletter"."submission_ptr_id") LEFT OUTER JOIN "patchwork_submission" T7 ON ("patchwork_coverletter"."submission_ptr_id" = T7."id") LEFT OUTER JOIN "patchwork_state" ON ("patchwork_event"."previous_state_id" = "patchwork_state"."id") LEFT OUTER JOIN "patchwork_state" T9 ON ("patchwork_event"."current_state_id" = T9."id") LEFT OUTER JOIN "auth_user" ON ("patchwork_event"."previous_delegate_id" = "auth_user"."id") LEFT OUTER JOIN "auth_user" T11 ON ("patchwork_event"."current_delegate_id" = T11."id") LEFT OUTER JOIN "patchwork_check" ON ("patchwork_event"."created_check_id" = "patchwork_check"."id") ORDER BY "patchwork_event"."date" DESC LIMIT 30

There is no universe in which a query with 11 JOINs will be fast.

I will see if that can be re-engineered to be faster and how breaking
that would be.

Regards,
Daniel

>
> Cheers,
> Stephen
> _______________________________________________
> Patchwork mailing list
> Patchwork at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/patchwork