#30685: Suboptimal QuerySet.distinct().count()
-------------------------------------+-------------------------------------
Reporter: Adam Sołtysik | Owner: nobody
Type: | Status: closed
Cleanup/optimization |
Component: Database layer | Version: 2.2
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Simon Charette):
It should feasible to adapt `sql.Query.get_count()` to perform these
optimizations by setting a `.values` mask when no columns are specified.
https://github.com/django/django/blob/05964b2198e53a8d66e34d83d9123e3051720b28/django/db/models/sql/query.py#L505-L514
You might have to tweak the suquery pushdown logic a bit as that's what
kicks in when `distinct` is used but it should be feasible.
https://github.com/django/django/blob/05964b2198e53a8d66e34d83d9123e3051720b28/django/db/models/sql/query.py#L421-L457
--
Ticket URL: <https://code.djangoproject.com/ticket/30685#comment:4>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/065.2ca440dc0e25922cf9a55d9f893be9f4%40djangoproject.com.
