| Message ID | 20180312123737.17047-2-dja@axtens.net |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix slow EventList API endpoint | expand |
diff --git a/patchwork/api/event.py b/patchwork/api/event.py index 0d97af227f0e..7e04b716af1a 100644 --- a/patchwork/api/event.py +++ b/patchwork/api/event.py @@ -96,7 +96,7 @@ class EventList(ListAPIView): def get_queryset(self): return Event.objects.all()\ - .select_related('project', 'patch', 'series', 'cover', - 'previous_state', 'current_state', - 'previous_delegate', 'current_delegate', - 'created_check') + .prefetch_related('project', 'patch', 'series', 'cover', + 'previous_state', 'current_state', + 'previous_delegate', 'current_delegate', + 'created_check')
select_related() creates a single giant query that JOINs the required tables together in the DB. prefetch_related() does a similar thing, but at the Django layer - for all referenced models, it makes a separate query to the DB to fetch them. This massively, massively simplifies the job the DB has to do: instead of creating a massive, sparse results table with many columns, we do 1 query for the events, and then query for only patches/cover letters/series/projects etc referenced in those 30 events. Tested with cURL (JSON output) + Postgres w/ ~100k patches, request time went from 1.5s to 0.25s, a 6x speedup. Tested with cURL (JSON output) + MySQL w/ ~33k patches, request time went from ~2.2s to ~0.20s, an ~11x speedup. Signed-off-by: Daniel Axtens <dja@axtens.net> --- patchwork/api/event.py | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)