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Changes between Initial Version and Version 1 of Ticket #37179

initial	v1
1	1	In `django.contrib.gis.gdal.layer`'s `Layer.__getitem__`, if a layer (with n features) does not support random read, slicing the layer would call `_make_feature` at most n times which this method scan the whole layer until feature id matched.
2	2
3		E.g. Slicing a layer for 3 features (id= 1,2,3) would scan the layer 3 times: [1] for id=1, [1,2] for id=2, [1,2,3] for id=3. Worse case would call `__iter__` (`capi.get_next_feature`) for n(n+1)/2 times
	3	E.g. Slicing a layer for 3 features (id= 1,2,3) would scan the layer 3 times: [1] for id=1, [1,2] for id=2, [1,2,3] for id=3. Worst case would call `__iter__` (`capi.get_next_feature`) for n(n+1)/2 times
4	4
5	5	A better iteration should scan the layer once only to get all features required. A possible [https://github.com/wongcht/django/pull/2/changes fix] FYR