This is a faily simple, albeit fairly large patch. Do we have any volunteers / naysayers?
This will be a big performance boost, and chx will not complain about the number of queries to url_alias when devel.module is enabled.
From Moshe's comment, do I understand that we will keep the multiple alias (i.e. one url can have multiple aliases), but only optimizing it where nodes are concerned?
Say "node/123" has an alias of "this_is_an_article". Are we going to have that alias in the url_alias table AS WELL AS in the node table? If so, this can lead to data integrity issues, where the alias in the node table says one thing and the ones in the url_alias says another. If we forbid node/123 aliases from going into the url_alias table, then it is not an issue.