 | | | AW: [suse-oracle] disk read and processes | AW: [suse-oracle] disk read and processes 2006-09-21 - By Frank Westheider
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Hi !
What are your io-settings for the database and the nfs?
Are you using Direct/Async-IO with NFS (filesystemio_options)?
Are you using TCP?
But: I saw the same performance-problem on other (non-NFS) IO-Systems even
with FTS.
Parallel is maxing out the IO-System, with normal FTS you won't get in these
areas.
Keep in mind: PQ is not moving the read blocks into the buffer-pool, so the
benefit of these fast reads is only for the current statement, not the other
sessions on the same object on the same instance!
Bye
Frank
-- --Urspr?ngliche Nachricht-- --
Von: Ronny Egner [mailto:Ronny.Egner@(protected)]
Gesendet: Donnerstag, 21. September 2006 10:17
An: suse-oracle@(protected)
Betreff: [suse-oracle] disk read and processes
Hi list,
i am struggling with i/o benchmarking and have a few questions:
Our central NAS system has performance issues with
nfs on solaris. When writing/reading over a gbit-link we see
"only" 35 mb/s within a single thread. When adding a second
thread (or process) the throughput increases - up to 80 mb/s with 4
threads (or processes).
However when writing data to disk with lets say 4 dbw processes
we can max out the 80 mb/s. But how does reading from disk relates
to that ? Lets say we do a full table scan in a single session and
therefore have to read the whole table - does oracle use more than
one process (or thread) to do that (remember my problem: one session
or thread can only read 35 mb/s at maximum speed) ?
--
Mit freundlichen Gr??en
Ronny Egner
Diplom-Ingenieur (BA)
SIV.AG
Konrad-Zuse-Stra?e 1
18184 Roggentin
Telefon: +49 (0)3 81 / 25 24 422
Telefax: +49 (0)3 81 / 25 24 399
mailto:ronny.egner@(protected)
http://www.siv.de
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