mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2025-08-04 02:48:35 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fixed #29563 -- Added result streaming for QuerySet.iterator() on SQLite.

Browse source
This commit is contained in:
Andrew Brown 2018-07-20 14:57:17 -04:00 • committed by Tim Graham
parent 55810d94d0
commit c0e3c65b9d
4 changed files with 31 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

17
docs/ref/models/querysets.txt
View file

@ -2178,10 +2178,15 @@ don't support server-side cursors.
Without server-side cursors
^^^^^^^^^^^^^^^^^^^^^^^^^^^
MySQL and SQLite don't support streaming results, hence the Python database
drivers load the entire result set into memory. The result set is then
transformed into Python row objects by the database adapter using the
``fetchmany()`` method defined in :pep:`249`.
MySQL doesn't support streaming results, hence the Python database driver loads
the entire result set into memory. The result set is then transformed into
Python row objects by the database adapter using the ``fetchmany()`` method
defined in :pep:`249`.
SQLite can fetch results in batches using ``fetchmany()``, but since SQLite
doesn't provide isolation between queries within a connection, be careful when
writing to the table being iterated over. See :ref:`sqlite-isolation` for
more information.
The ``chunk_size`` parameter controls the size of batches Django retrieves from
the database driver. Larger batches decrease the overhead of communicating with
@ -2195,6 +2200,10 @@ psycopg mailing list <https://www.postgresql.org/message-id/4D2F2C71.8080805%40d
between the number of rows transferred and the data discarded if the loop
is exited early.
.. versionchanged:: 2.2
Support for result streaming on SQLite was added.
``latest()``
~~~~~~~~~~~~