Originally posted by julian
I can't provide any URL that proves that
:-) That's what I thought...
Ok, I'll change my answer. *Any* oracle Concepts manual (lots of URLs ) proves that. There you'll find that if Oracle need to find *any* information abot the rows in a table it can only find that information by reading it from coresponding database blocks. Isn't this self evident? (If you'll ask me to specify where in the manuals this is written I'll ignore that question .)

You are asking Oracle "How many rows there are in table TEST?".
No, I was asking about the PUZZLE, did you make it or did you see it somewhere.
???? Isn't your answer to my comment a little out of the context?

Where can Oracle get this information from? Only by reading blocks that hold those values.
Reading the blocks or the block headers?
Aren't you desperately trying to pull yourself out by reaching for straws? Block header is nothing but a part of the block. Your original claim was that (persumably) in 8i Oracle doesn't have to read blocks if you are asking only for pseudo columns and not for the real columns. My point was: blocks must be touched no matter if you don't realy select any particular column values.

(Oh, I just discovered that I made a typo in the following senrtence of my explanation: "Where can Oracle get this information from? Only by reading blocks that hold those values." It realy should be: "... Only by reading blocks that hold those rows)