Oracle datafile autoextend question

Question

If I have 2 datafiles attached to a tablespace, and BOTH are set to AUTOEXTEND and BOTH are set to unlimited, will Oracle know to extend both datafiles, or only extend one of them. I have read through many manuals, but none of them answer this question. As to why this is set like this, well, it's an inherited system that I am starting to tune.

Answer 1

It depends on how much disk space you have (among other things). "Unlimited" in this context means "to the largest supported table size on your platform" not "grab up all the disk space even if you can't use it." If you have enough disk space for two maximum-sized datafiles, you should be fine.

Also (possibly dumb question) since this is an existing application, why can't you just look and see what it did?

-- MarkusQ

Answer 2

If you have 2 datafiles in the same tablespace, oracle will only fill/extend the 2nd, when the first one is filled to its maxsize.

If you have unlimited on the first, there will be no reason (at least that I can think of right now) when oracle itself will fill/use/extend the 2nd datafile.

Even if you have run out of space on the first Datafile's filesystem/ASM/whatever, I'm quite sure, Oracle will still try to extend the 1st datafile (At least that's what I think I saw just a few hours ago :P).

Please anyone, correct me if I'm wrong.