Re: Oracle "REDO WASTAGE" statistic

When a commit takes place the log writer writes in units of what it thinks the
operating system block size is. Redo Wastage is the amount of padding that
is needed to fill the last block of the current write.

If your redo wastage is roughly 'redo writes * o/s block size / 2' (i.e. each
redo write wastes on average half a block) then your wastage is 'reasonable' even though it may appear to be large in absolute terms.

NB What you consider to be the O/S block size is not necessarily the

same as what Oracle thinks. To find out what Oracle thinks (approx.)

take: 'redo written + redo wastage'/'redo blocks written' to within about 14 bytes this will
probably be 512 or 1024 and is roughly the size that Oracle considers a block
to be.

Rob_evelyn_at_B-f.com wrote in article <5upd8k$2us_at_drn.zippo.com>...
> I am seeing a large "REDO WASTAGE" in my statisitcs. According to
 the ORacle
> manuals, this is the "UNUSED" space in the redo log. How is
 wastage created
> and how do I reduce the wastage ?
>
> Thanks Rob Evelyn
> Rob_Evelyn_at_B-f.com
>
  Received on Fri Sep 05 1997 - 00:00:00 CDT