Oracle Tips

First define trace identifier for generated trace files so we can easily identify our trace files in UDUMP folder.

SQL> alter session set tracefile_identifier='MYSESSION';
Enable 10046 tracing.

SQL> alter session set events '10046 trace name context forever, level 8';
Now execute SQL Statements...

select e.empno, e.ename, d.dname, d.deptno
from emp e , dept d
where e.deptno = d.deptno;
Disable 10046 tracing.

SQL> alter session set events '10046 trace name context off';
Check UDUMP directory for generated trace file.
file name like "XXXX_MYSESSION.TRC"

C:\Oracle\admin\ora9i\udump>dir *MYSESSION.trc
Now generated trace file is RAW trace file and very hard to read and understand ...so through TKPROF utility create readable output file for generated trace file.

C:\Oracle\admin\ora9i\udump>tkprof ORA01904_MYSESSION.TRC c:\output.log

TKPROF: Release 10.1.0.5.0 - Production on Wed Oct 17 19:01:44 2007

Copyright (c) 1982, 2005, Oracle. All rights reserved.
Open c:\output.log file and analyze it. below is content of output.log file

select e.empno, e.ename, d.dname, d.deptno
from emp e , dept d
where e.deptno = d.deptno

call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.29 0.31 2 0 2 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 2 0.00 0.00 3 30 2 14
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 4 0.29 0.31 5 30 4 14

Misses in library cache during parse: 1
Optimizer mode: CHOOSE
Parsing user id: 66

---Below is execution plan

Rows Row Source Operation
------- ---------------------------------------------------
14 NESTED LOOPS
14 TABLE ACCESS FULL EMP
14 TABLE ACCESS BY INDEX ROWID DEPT
14 INDEX UNIQUE SCAN (object id 32119)

---Waits time information.

Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 2 0.00 0.00
db file sequential read 3 0.00 0.00
SQL*Net message from client 2 56.49 56.51