Karl Reitschuster's Tech Space

Hi reader;

Tanel Poder holds a 2 day session in Düsseldorf last week; This was not my first Tuning/Troubleshooting training. But it was extraordinary what Tanel showed us when usual ways would not work.

In short a must attend program for DBA's Troubleshooters and Advanced database developers which are noz afraid of a taking a look deeper and are not afraid of low level techniques/items like traces, debugging, signals, dumps, stacks, memory structures ...;

Additionally Tanel is very busy in introducing a lot of examples giving an impression  about that it works what he is teaching. Great too are many scripts provided by Tanel and downloadable from his web site; One of the most famous is snapper a vmstat like tool capturing stats, waits and database timing model delta data between snapshots. Very useful!

an example snapping the DBWRITER session on an Oracle Database with the interval of 5 seconds...

SQL> @snapper out 5 1 565

-- Session Snapper v1.09 by Tanel Poder ( http://www.tanelpoder.com )

---------------------------------------------------------------------------------------------------------------------------------------------
HEAD, SID, SNAPSHOT START , SECONDS, TYPE, STATISTIC , DELTA, DELTA/SEC, HDELTA, HDELTA/SEC
---------------------------------------------------------------------------------------------------------------------------------------------
DATA, 565, 20081110 16:17:01, 5, STAT, messages sent , 1, 0, 1, ,2
DATA, 565, 20081110 16:17:01, 5, STAT, messages received , 1, 0, 1, ,2
DATA, 565, 20081110 16:17:01, 5, STAT, physical write total IO requests , 1963, 393, 1,96k, 392,6
DATA, 565, 20081110 16:17:01, 5, STAT, physical write total multi block request, 34, 7, 34, 6,8
DATA, 565, 20081110 16:17:01, 5, STAT, physical write total bytes , 17080320, 3416064, 17,08M, 3,42M
DATA, 565, 20081110 16:17:01, 5, STAT, physical writes , 2085, 417, 2,09k, 417
DATA, 565, 20081110 16:17:01, 5, STAT, physical writes from cache , 2085, 417, 2,09k, 417
DATA, 565, 20081110 16:17:01, 5, STAT, physical write IO requests , 1983, 397, 1,98k, 396,6
DATA, 565, 20081110 16:17:01, 5, STAT, physical write bytes , 17080320, 3416064, 17,08M, 3,42M
DATA, 565, 20081110 16:17:01, 5, STAT, physical writes non checkpoint , 330, 66, 330, 66
DATA, 565, 20081110 16:17:01, 5, STAT, summed dirty queue length , 44, 9, 44, 8,8
DATA, 565, 20081110 16:17:01, 5, STAT, DBWR checkpoint buffers written , 2047, 409, 2,05k, 409,4
DATA, 565, 20081110 16:17:01, 5, STAT, DBWR thread checkpoint buffers written , 2046, 409, 2,05k, 409,2
DATA, 565, 20081110 16:17:01, 5, STAT, DBWR undo block writes , 44, 9, 44, 8,8
DATA, 565, 20081110 16:17:01, 5, STAT, redo entries , 1, 0, 1, ,2
DATA, 565, 20081110 16:17:01, 5, STAT, redo size , 65540, 13108, 65,54k, 13,11k
DATA, 565, 20081110 16:17:01, 5, TIME, background cpu time , 320000, 64000, 320ms, 64ms
DATA, 565, 20081110 16:17:01, 5, TIME, background elapsed time , 19137199, 3827440, 19,14s, 3,83s
-- End of snap 1

PL/SQL-Prozedur erfolgreich abgeschlossen.

Karl