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
25892	Optimize SeparateDatabaseAndState.database_backwards() by caching intermediate state	Amos Onn	Amos Onn	The database_backwards of SeparateDatabaseAndState runs at O(n^2^) where n is the number of database_operations. For each operation, it regenerates the state up to it from the first operation. Instead, we could cache all the intermediate states, similar to the implementation of _migrate_all_backwards in the migration executor (or migrate in django 1.8.x).	Cleanup/optimization	closed	Migrations	1.8	Normal	fixed			Accepted	1	0	0	0	0	0