Hi

I was wondering how Oracle handles these 2 situations:

1. A select is fetching 1 million rows but the buffer cache can only 500000 rows (in blocks), will Oracle fetch 500000 rows first then return to user then age out these 500000 rows fetch the rest, 500000 rows again and return to user?

2. The same select is fetching 1 million rows again but in this case the buffer cache is large, can handles 2 million rows (in blocks), but is half full, in other words it has to age out the old buffers. The question is are the old blocks age out then fetch or it first fetch then age out?

cheers