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| author | Daniel Axtens <dja@axtens.net> | 2018-03-12 22:07:15 +1100 |
|---|---|---|
| committer | Daniel Axtens <dja@axtens.net> | 2018-04-05 19:21:05 +1000 |
| commit | 5d9b00409fcafc7b8cd09400195c9c9f1b3e4fcc (patch) | |
| tree | d9624103c389cf507ffc8ea3800881223bd6309b | |
| parent | 5bc66c8e3c9d6de9d57705ee5d2e4797e84757cb (diff) | |
| download | patchwork-5d9b00409fcafc7b8cd09400195c9c9f1b3e4fcc.tar patchwork-5d9b00409fcafc7b8cd09400195c9c9f1b3e4fcc.tar.gz | |
api: EventList: change select_related() to prefetch_related()
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 renderer + Postgres w/ ~100k patches,
request time went from 1.5s to 0.25s, a 6x speedup.
Tested with cURL + JSON renderer + MySQL w/ ~33k patches,
request time went from ~2.2s to ~0.20s, an ~11x speedup.
Signed-off-by: Daniel Axtens <dja@axtens.net>
| -rw-r--r-- | patchwork/api/event.py | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/patchwork/api/event.py b/patchwork/api/event.py index 0d97af2..7e04b71 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') |