Opened 15 years ago

Closed 15 years ago

Last modified 13 years ago

#13156 closed (fixed)

exists() selects all columns

Reported by: Karen Tracey Owned by: nobody
Component: Database layer (models, ORM) Version: dev
Severity: Keywords:
Cc: Triage Stage: Accepted
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description

It doesn't seem like the behavior noted here: http://groups.google.com/group/django-developers/browse_thread/thread/186f933bf51f1fa0

ever got written up in a ticket. Besides exists() not being as efficient as documented, it used to be that the internal existence queries done by the ORM to check for existence of an object and decide whether to do an INSERT or UPDATE just pulled a constant 1 from the DB, not all columns of the instance being queried. Now these existence queries are pulling the 1 and all columns of the instance, which seems like it could be a performance regression.

Change History (3)

comment:1 by Russell Keith-Magee, 15 years ago

Triage Stage: UnreviewedAccepted

comment:2 by Russell Keith-Magee, 15 years ago

Resolution: fixed
Status: newclosed

(In [12810]) Fixed #13156 -- Ensure that exists() queries are as fast as they can be. Thanks to Jerome Leclanche for the report.

comment:3 by Jacob, 13 years ago

milestone: 1.2

Milestone 1.2 deleted

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