Loading EquipmentObjects#index is molasses

[mnquintana]

Don't know how I didn't notice the slowness before, but:

I have 1000 equipment items associated with 100 equipment models in 10 categories. When I load /equipment_objects/, I see this:

It took over 34 secs (!) to render this view, and there were over 2200 individual SQL queries. Seems like something like 2 queries per item. This is consistent on every page load.

[squidgetx]

lol

edit: looking into it now

edit2: ok, found the culprit, it's two fold. first, there's an n+1 query (we should be eager loading the equipment models) but more importantly, we're doing a lot of work when making the deactivate button which I think was introduced in #1052 which I reviewed: looks like I didn't catch this.

Anyway the easiest solution is to just remove the deactivate button from the view but we may want to think about a deactivate button that asks the server for the information it needs only after its clicked

[orenyk]

Oh, that makes sense - all of that availability checking takes work. The other thing is that I believe we're loading the entire table in JS and then paginating, this is also part of the issue w/ the reservations index (see #708).

I'm in favor of conditionally removing the button. When our controller is EquipmentObjectsController (e.g. we're getting all of the equipment items), we shouldn't show a deactivate button (to be honest, this is a bit of a silly view, but whatever :-P). When our controller is EquipmentModelsController we should show the deactivate button since we're either in /equipment_models/:id/ or /equipment_models/:id/equipment_objects so our list should be much shorter. This would be a simple change to the view (either checking the params or setting a local variable in the controllers) and should help with the global index.

[orenyk]

Also, in terms of checking for availability after clicking, I think that would be bundled w/ #1061 since at the moment we're passing results into the JS; I'm not sure how easy it would be with our current backend to query the server via JS (but maybe I'm just not JS-savvy enough :-P).

[squidgetx]

Okay, removing the button helps a lot (now we're only down to N queries instead of 3N queries) Still not constant time because the equipment object status call requires a few queries as well -_-