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Changes between Version 1 and Version 2 of Ticket #17459, comment 1

v1	v2
1	1	After thinking about this for a while, I think it's not something Django should do implicitly.
2	2
3		First of all, because this results in some serious performance drawback that's hidden in a place you normally wouldn't expect it to be and it gives a false impression of Django supporting cross-database queries ~~(which we don't)~~.
	3	First of all, because this results in some serious performance drawback that's hidden in a place you normally wouldn't expect it to be and it gives a false impression of Django supporting cross-database queries.
4	4
5	5	Second, because it's not always the right thing to do. Taking the (naive) example of master-slave configuration from the docs, the fact that the router returns different slaves for Bar and Foo, shouldn't prevent Django from generating the subquery. As Django has no other way of knowing, which dbs contain which tables, we can't assume that the table is or isn't there.