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Diffstat (limited to 'docs/topics/db/optimization.txt')
| -rw-r--r-- | docs/topics/db/optimization.txt | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/docs/topics/db/optimization.txt b/docs/topics/db/optimization.txt index dda7e9504a..baea968fdb 100644 --- a/docs/topics/db/optimization.txt +++ b/docs/topics/db/optimization.txt @@ -224,21 +224,21 @@ many-to-many relation to User, the following template code is optimal: It is optimal because: - 1. Since QuerySets are lazy, this does no database queries if 'display_inbox' - is False. +1. Since QuerySets are lazy, this does no database queries if 'display_inbox' + is False. - #. Use of :ttag:`with` means that we store ``user.emails.all`` in a variable - for later use, allowing its cache to be re-used. +#. Use of :ttag:`with` means that we store ``user.emails.all`` in a variable + for later use, allowing its cache to be re-used. - #. The line ``{% if emails %}`` causes ``QuerySet.__nonzero__()`` to be called, - which causes the ``user.emails.all()`` query to be run on the database, and - at the least the first line to be turned into an ORM object. If there aren't - any results, it will return False, otherwise True. +#. The line ``{% if emails %}`` causes ``QuerySet.__nonzero__()`` to be called, + which causes the ``user.emails.all()`` query to be run on the database, and + at the least the first line to be turned into an ORM object. If there aren't + any results, it will return False, otherwise True. - #. The use of ``{{ emails|length }}`` calls ``QuerySet.__len__()``, filling - out the rest of the cache without doing another query. +#. The use of ``{{ emails|length }}`` calls ``QuerySet.__len__()``, filling + out the rest of the cache without doing another query. - #. The :ttag:`for` loop iterates over the already filled cache. +#. The :ttag:`for` loop iterates over the already filled cache. In total, this code does either one or zero database queries. The only deliberate optimization performed is the use of the :ttag:`with` tag. Using |