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Fixed #16895 -- Warned about cost of QuerySet ordering

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Thanks outofculture at gmail.com for the suggestion.
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e0ne 2013-09-08 22:57:36 +03:00 • committed by Tim Graham
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11
docs/topics/db/optimization.txt
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@ -306,6 +306,17 @@ instead of::
entry.blog.id
Don't order results if you don't care
-------------------------------------
Ordering is not free; each field to order by is an operation the database must
perform. If a model has a default ordering (:attr:`Meta.ordering
<django.db.models.Options.ordering>`) and you don't need it, remove
it on a ``QuerySet`` by calling
:meth:`~django.db.models.query.QuerySet.order_by()` with no parameters.
Adding an index to your database may help to improve ordering performance.
Insert in bulk
==============