#26063: Regression in Django 1.9: SQLite can no longer handle more than 2000 
values
in a "foo__in" filter
----------------------------------------------+--------------------
     Reporter:  rhertzog                      |      Owner:  nobody
         Type:  Bug                           |     Status:  new
    Component:  Database layer (models, ORM)  |    Version:  1.9
     Severity:  Normal                        |   Keywords:
 Triage Stage:  Unreviewed                    |  Has patch:  0
Easy pickings:  0                             |      UI/UX:  0
----------------------------------------------+--------------------
 Commit 4f6a7663bcddffb114f2647f9928cbf1fdd8e4b5 introduced a regression in
 Django 1.9 because you can no longer have a queryset of the form {{{
 Model.objects.filter(foo__in=array) }}} with more than 2000 items in
 {{{array}}}.

 The above changes generates a “SELECT QUOTE(?), ..., QUOTE(?)” query with
 as many values as items in the array. This will hit the SQLite limit
 SQLITE_MAX_COLUMN which defaults to 2000 and can only be increased up to
 32767.

 Before this change we were only limited by SQLITE_MAX_VARIABLE_NUMBER
 which is lower by default (999) but which can be increased to a much
 higher value. In Debian for example we use a value of 250000.

 While the latter limit was unreasonably low (it just costs a bit of memory
 and you can expect to have many parameters), the former limit make much
 more sense IMO and I don't expect distributions to override the upstream
 value.

 I'm not sure what's the best way forward. Possibly process parameters by
 batch of 2000.

 (This bug has been initially reported in https://bugs.debian.org/809211 )

--
Ticket URL: <https://code.djangoproject.com/ticket/26063>
Django <https://code.djangoproject.com/>
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