#28459: Improve performance of QuerySet
-------------------------------------+-------------------------------------
     Reporter:  Sergey Fedoseev      |                    Owner:  nobody
         Type:                       |                   Status:  closed
  Cleanup/optimization               |
    Component:  Database layer       |                  Version:  master
  (models, ORM)                      |
     Severity:  Normal               |               Resolution:  fixed
     Keywords:                       |             Triage Stage:  Accepted
    Has patch:  1                    |      Needs documentation:  0
  Needs tests:  0                    |  Patch needs improvement:  0
Easy pickings:  0                    |                    UI/UX:  0
-------------------------------------+-------------------------------------

Comment (by Sergey Fedoseev):

 [https://github.com/django/django/pull/8878 PR (Improved performance of
 loading DecimalField on SQLite)]
 Before:
 {{{
 In [5]: %timeit for x in Test.objects.values_list('decimal'): pass
 150 ms ± 1.76 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
 In [6]: %timeit for x in Test.objects.values_list(models.F('decimal') +
 1): pass
 123 ms ± 1.08 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
 }}}
 After:
 {{{
 In [2]: %timeit for x in Test.objects.values_list('decimal'): pass
 28.8 ms ± 1.05 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
 In [3]: %timeit for x in Test.objects.values_list(models.F('decimal') +
 1): pass
 84.6 ms ± 541 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
 }}}

-- 
Ticket URL: <https://code.djangoproject.com/ticket/28459#comment:16>
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