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. Regards Wolfgang Breitling Centrex Consulting Corporation www.centrexcc.com -- //www.freelists.org/webpage/oracle-l