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Home -> Community -> Mailing Lists -> Oracle-L -> RE: RAC/ASM Help
Right you are. Wrongly stated on my part. As far as I know, only three
things change the layout and structure: 1) Rebalancing following a storgage
change like adding or removing a disk, 2) Opening a new database file, and
3) extending an existing database file.
ASM does not yet react to “heat” except when the the “heat” results in extending the database file. Then when the file extends, instead of possibly staying on a single spindle in contiguous space avoiding seeks for the streaming batch case, the new blocks will be spread evenly across the group. So ASM can in fact mess up planned sequential streaming, but I attributed it to entirely the wrong reason (wishful thinking and a brain cramp on my part).
Regards,
mwf
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]On
Behalf Of Lawie, Duncan
Sent: Monday, October 23, 2006 10:17 AM
To: 'mwf_at_rsiz.com'; shivaswamykr_at_gmail.com; oracle-l_at_freelists.org
Subject: RE: RAC/ASM Help
Shiva,
have a look at this EMC / Oracle Joint Paper for ASM on EMC http://www.oracle.com/technology/products/database/asm/pdf/asm-on-emc-5_3.pd f
Mark,
Do you have heavily i/o intensive batch jobs that have a potential to stream (which may be interpreted by ASM as a hot spot when in fact it is maximum throughput with minimized seek overhead)?
Is this meaningful? It was my understanding that ASM has no real knowledge/understanding of "hot spots", and relies simply on spreading data thinly to avoid them.
Cheers,
Duncan.
http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Oct 23 2006 - 16:26:20 CDT
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