Then you need to account for the namespaces too.
not going to make MySQL happy: (xx_namespace = ... AND xx_title = ...)
OR (xx_namespace = ... AND xx_title = ...) OR ... I don't think
there's a way to do that with IN.
(xx_namespace=... AND xx_title IN (whitelist1)) OR (xx_namespace=...
AND xx_title IN (whitelist2)) OR ...
That reduces it to one term per namespace rather than one term per
whitelist item. As long as you don't include namespaces for which the
whitelist is empty, that should be an improvement.