Regarding Performance: It depends, but yes, CROSS APPLY can be used in place of an INNER JOIN in some situations to realize a performance benefit. It's only going to work in cases where you're using a table expression, meaning a table value function or a sub-query. Generally, if you know that there's a one-to-one relation between the left and right side of a join (inner or outer), CROSS APPLY or OUTER APPLY can be used. Circumstances are different (indexes, statistics, etc.) so test it for the queries you're writing, but it does work.