RE: Help with SQL Tuning

  • From: "Taylor, Chris David" <Chris.Taylor@xxxxxxxxxxxxxxx>
  • To: "Wolfgang Breitling" <breitliw@xxxxxxxxxxxxx>
  • Date: Thu, 6 Dec 2007 08:37:25 -0600

Well phooey.  I guess I should have double checked that before replying.

Chris Taylor
Sr. Oracle DBA
Ingram Barge Company
Nashville, TN 37205
Office: 615-517-3355
Cell: 615-354-4799
Email: chris.taylor@xxxxxxxxxxxxxxx

-----Original Message-----
From: Wolfgang Breitling [mailto:breitliw@xxxxxxxxxxxxx] 
Sent: Thursday, December 06, 2007 8:08 AM
To: Taylor, Chris David
Cc: Oracle-L Freelists
Subject: RE: Help with SQL Tuning

At 06:45 AM 12/6/2007, Taylor, Chris David wrote:
>Well there are a couple of things here if I'm not mistaken.
>1.) Full table scans almost always use sequential file reads versus 
>db file scattered reads

It's the other way around, Full scans (not only full table scans) 
generally use predominantly "db file scattered reads".  "db file 
sequential reads" are single block reads, most used by index lookups 
but could e.g. also be used by an FTS to chase chained rows.


Wolfgang Breitling
Centrex Consulting Corporation 


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