Pls forgive the repost, i'm cross-posting in comp.unix.aix in hopes i
can scare up an opinion... <G>
> Hi
> A DB2 instructor informed us that AIX Asynchronous IO (AIO) with UDB
is
> _NOT_ recommended, apparently because of the issue of _absolute_
> transaction recoverability, even w/ DMS raw logical volumes.
> The instructor seemed sure of his facts, but didn't provide any
> supporting documentation before he left (darn!). Can anyone comment on
> his claim?
> I understand DB2 does a lot of its own AIO in its IO servers, and I'm
> wondering if that's the crux of the issue.
> I _DID_ see a claim in this n.g. that asynch. IO is "a good thing"
> referencing a supposed redbook "Database Performance on AIX in DB2 UDB
> and Oracle Environments "SG24-551-00". Problem is I can't find that
> comment?)
> Using RLVs alone can increase performance by about a fifth, I'm
> wondering what kind of performance margin increase is to be gained
from
> AIO. Sybase requires it to install (as does, apparently, Oracle), but
> DB2 UDB doesn't require it.
> TIA,
> /leebert
Before you buy.