segments/extents ? maxextents?

Two questions that relate to Tablespace and Table creation:

The manuals say not to create an rollback segment tablespace with unlimited
maxextents. So what do I choose and why? What about initaial and next? For a small database <500M I was imagining a 10M datafile with default storage (initial 256K next 256K minextents 2 maxextents 4096

                 pctincrease 0 )
Does this mean that my RB segments are 256K or each extent is 256K or both?
Do you figure out the max size of a rollback segment by initial x maxextents ?
In which case 4096 would be larger than 10M so then I could figure out maxextents by filesize / initial ( as long as next is the same
and pctincrease = 0 )? Is this wrong?
This calcualtion would yield 10M/256K= 37.9 extents or 37 depending on how the
block size internal rounding would work.  

This question actually led me to question #2 which is when you create a table what is the size of the segment? I have heard that you should try ( but not too hard to get your tables or objects (
especially static tables) into one segment which if what I said above is true
for a 1M static table I would want the storage clause for the table to be
storage clause ( initial 1M next 256k pctincrease 0 minextents 1 maxextents 4 )
This would allow the table to double in size up to 2M?

Am I way off with this stuff the Oracle 8i DBA handbook is good but only if you really understand the guts of oracle which I am attempting to do.

I guess to summarize:
Is intial the size of your segment?
Does does initial + ( maxextent * next ) < datafile size make sense And how do you decide on the RBS initial & max

Does DB_Block_Size get figured into any of this?

Thanks for any help in advance.

Rob Received on Sun Oct 14 2001 - 15:38:27 CDT