Opened 5 years ago
Last modified 5 years ago
#30842 closed Cleanup/optimization
Prefetch_related spends considerable time constructing querysets. — at Version 1
| Reported by: | Alex Aktsipetrov | Owned by: | nobody |
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| Component: | Database layer (models, ORM) | Version: | dev |
| Severity: | Normal | Keywords: | prefetch_related |
| Cc: | Simon Charette | Triage Stage: | Accepted |
| Has patch: | yes | Needs documentation: | no |
| Needs tests: | no | Patch needs improvement: | no |
| Easy pickings: | no | UI/UX: | no |
Description (last modified by )
As part of the bugfix django started constructing N+1 querysets during a typical prefetch_related call while only 2 sql queries are executed.
This adds a noticeable slowdown. Attaching the flamegraph for queryset fetching 100 objects, roughly 2/3 of the time are spent there.
Change History (2)
by , 5 years ago
| Attachment: | prefetch.svg.gz added |
|---|
comment:1 by , 5 years ago
| Description: | modified (diff) |
|---|
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