Buddypress widgets vs post-indexer

Hi

Does buddypress collects global site posts and other dara in seperate tables like post-indexer does? If thats the case, should we use post-indexer to display for example Global recent posts or is it better to use "Recent sitewide posts" widget which comes with buddypress?

If i use post-indexer with buddypress, does it mean that this setup will use more server resources?

Sorry if its an obvious thing or it has been discussed before... didn't find anything through search.