id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
25914	order_by not consistently returning data in specified order	shmkrause	nobody	"When ordering model records by timestamp and slicing, where the start parameter has not been specified, the query does not pull data in the order specified.

To be more specific, the code I have is:
data = MyModel.objects.order_by('-timestamp')[:100]

Output ordering is not consistent; expected data should all be from today (December 10, 2015), but data returned is stamped either December 1, 2015 or December 10, 2015.  There is no discernible pattern as to when data from the first and the tenth is given. 

Note that adding the start parameter for the slice stops this behaviour from occurring.
"	Bug	closed	Database layer (models, ORM)	1.8	Normal	needsinfo			Unreviewed	0	0	0	0	0	0