Fixed #21986 -- Added some guidelines for database indexes.

Thanks django-issues at colons.co for the suggestion.
This commit is contained in:
Alex de Landgraaf 2014-02-23 13:55:25 +01:00 committed by Tim Graham
parent 5a4f1298cf
commit c8d61fa109
1 changed files with 11 additions and 3 deletions

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@ -36,11 +36,19 @@ Use standard DB optimization techniques
...including:
* Indexes. This is a number one priority, *after* you have determined from
* Indexes_. This is a number one priority, *after* you have determined from
profiling what indexes should be added. Use
:attr:`django.db.models.Field.db_index` or
:attr:`Field.db_index <django.db.models.Field.db_index>` or
:attr:`Meta.index_together <django.db.models.Options.index_together>` to add
these from Django.
these from Django. Consider adding indexes to fields that you frequently
query using :meth:`~django.db.models.query.QuerySet.filter()`,
:meth:`~django.db.models.query.QuerySet.exclude()`,
:meth:`~django.db.models.query.QuerySet.order_by()`, etc. as indexes may help
to speed up lookups. Note that determining the best indexes is a complex
database-dependent topic that will depend on your particular application.
The overhead of maintaining an index may outweigh any gains in query speed.
.. _Indexes: http://en.wikipedia.org/wiki/Database_index
* Appropriate use of field types.