Files
openfoodnetwork/app/controllers/spree
Pau Perez c85d00fcb8 Remove N+1 while fetching distributors of OCs
What used to be done as

```sql
SELECT "order_cycles".* FROM "order_cycles"
WHERE (order_cycles.orders_open_at <= '2019-07-29 17:45:20.137294'
  AND order_cycles.orders_close_at >= '2019-07-29 17:45:20.137333')

SELECT DISTINCT "enterprises".* FROM "enterprises"
INNER JOIN "exchanges" ON "enterprises"."id" = "exchanges"."receiver_id"
WHERE "exchanges"."order_cycle_id" = 1
  AND "exchanges"."incoming" = 'f'
(...)
SELECT DISTINCT "enterprises".* FROM "enterprises"
INNER JOIN "exchanges" ON "enterprises"."id" = "exchanges"."receiver_id"
WHERE "exchanges"."order_cycle_id" = 4
  AND "exchanges"."incoming" = 'f'
```

it became

```sql
SELECT "order_cycles".* FROM "order_cycles"
WHERE (order_cycles.orders_open_at <= '2019-07-29 17:45:20.137294'
  AND order_cycles.orders_close_at >= '2019-07-29 17:45:20.137333')

SELECT "exchanges".* FROM "exchanges"
WHERE "exchanges"."incoming" = 'f'
  AND "exchanges"."order_cycle_id" IN (1, 2, 3, 4)

SELECT "enterprises".* FROM "enterprises"
WHERE "enterprises"."id" IN (3, 4, 5, 6)
```

I haven't got any perf numbers yet but each of the N+1 queries took as
long as the single `enterprises` query on my dev machine.

This should have a noticeable perf impact since the changed method
belongs to the `BaseController` seems to be executed in all HTML
requests as it gets called by

```ruby
before_filter :warn_invalid_order_cycles, if: :html_request?
```
2019-07-29 20:02:47 +02:00
..
2019-06-18 10:49:20 +01:00
2019-06-18 10:49:20 +01:00
2019-06-18 10:49:20 +01:00
2019-07-08 14:06:01 +01:00