RE: extent allocation

  • From: Paul Drake <discgolfdba@xxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Tue, 22 Jun 2004 22:02:15 -0700 (PDT)

--- Jacques Kilchoer <Jacques.Kilchoer@xxxxxxxxx>
> The next question is, what size should you make your
> uniform extents?
> A: Since number of extents is irrelevant (this also
> seems to be the
> consensus on this list), then I would say that the
> extent size doesn't
> really matter either.

I did not catch the OS of the OP.

not even a good guess of a multiple of the db file
multiblock read count times the database block size?

on win32 OSes, I've seen no discounting of the dbfmbrc
down from either 16 or 32 during full table scans
against RAID volumes with a stripe size of 256 KB (8KB
block size).

so why not start with an extent size of 128 KB for
small and go from there?
If you have 10,000 tables and indexes that only have 5
blocks allocated, you might want to go smaller.

In that case, you might want to use a 2 KB block size
and put them in their own tablespace and buffer pool


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