For the record, 'db file sequential read' isn't ALWAYS a single-block read. There are cases in which you can see 'db file sequential read' events with p3>1. It happens (well, happened) when the kernel reads from a data file directly into a user's non-shared process space (not the SGA). It used to happen in Oracle7.3 when reading sort segments from disk into a PGS. Nowadays, these reads are done with the event 'direct path read'.
It is true that 'db file scattered read' will never have p3=1. Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com Upcoming events: - Hotsos Clinic 101 in Dallas, Washington, Denver, Sydney - Hotsos Symposium 2004, March 7-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- Wolfgang Breitling Sent: Wednesday, June 11, 2003 3:55 PM To: Multiple recipients of list ORACLE-L Yes, 'db file sequential read' is always a single block read. It is 'db file scattered read' which is <= DB_FILE_MULTIBLOCK_READ_COUNT At 10:35 AM 6/11/2003 -0800, you wrote: >A SINGLE block? I was convinced that it was <= DB_FILE_MULTIBLOCK_READ_COUNT >blocks. >Are you sure? > >Mladen Gogala >Oracle DBA >Phone:(203) 459-6855 >Email:[EMAIL PROTECTED] > > >-----Original Message----- >Sent: Wednesday, June 11, 2003 2:19 PM >To: Multiple recipients of list ORACLE-L > > >Dennis: > >THe event 'db file sequential read' is NOT always an INDEX Scan. It is >just a single block read which TYPICALLY happens during an INDEX scan. >The word 'TYPICALLY' is the key here. > > > >Best Regards, >K Gopalakrishnan Wolfgang Breitling Oracle7, 8, 8i, 9i OCP DBA Centrex Consulting Corporation http://www.centrexcc.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Wolfgang Breitling INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Cary Millsap INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
