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RE: db_file_multiblock_read_count causing full scans to takelonger?

From: Kevin Closson <kevinc_at_polyserve.com>
Date: Tue, 19 Dec 2006 14:18:04 -0800
Message-ID: <5D2570CAFC98974F9B6A759D1C74BAD001C33830@ex2.ms.polyserve.com>

 

If this is UFS, you should be able to tunefs to set fs_maxcontig to limit the size of the gobbling an FS read-ahead reads in. The wont control just how far a read-ahead reaches though.

What you need (and I don't know how to track this on HPUX) is visibility into the read-ahead blocks visited. All Fses I've worked on track that. It is important to know whether or not RA is getting triggered for stuff that never gets visited.

>>>-----Original Message-----
>>>From: Kevin Lidh [mailto:kevin.lidh_at_gmail.com]
>>>Sent: Tuesday, December 19, 2006 1:22 PM
>>>To: kevinc_at_polyserve.com
>>>Cc: oracle-l_at_freelists.org
>>>Subject: RE: db_file_multiblock_read_count causing full
>>>scans to takelonger?
>>>
>>>In my case, it's filesystem. Is there a parameter that
>>>determines read-aheads? I'll look for HP-UX but if you know
>

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Received on Tue Dec 19 2006 - 16:18:04 CST

Original text of this message

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