1.Trace file简介:
Trace file（追踪文件)是以trc为后续的文本文件,它记录了各种sql操作及所消耗的时间等,根据trace文件我们就可以了解哪些sql导致了系统的性能瓶颈，进而采取恰当的方式调优.
2.怎么生成trace file:
1. 首先用sqlplus登陆Oracle.
show parameter sql_trace
Name Type Value
-------------------------------------------
sql_trace boolean false
如果value是false表示系统当前不会产生trace文件.采取如下操作让系统产生trace文件:
alter session set sql_trace=true;
或者:alter system set sql_trace=true;
2.执行一些sql语句后.停止产生trace文件.
alter session(或system) set sql_trace=false.
3.trace文件所在的默认路径.
SELECT VALUE FROM V$PARAMETER WHERE NAME = 'user_dump_dest'
我本机的查找结果是:C:\ORACLE\PRODUCT\10.2.0\ADMIN\ORA102\UDUMP.
3.怎么更改trace文件的保存目录:
如果是oracle 11g 以下的版本则:alter system set user_dump_dest = 'd:\oracle\trace';(注意:trace文件就直接生成在trace目录下)
如果是oracle 11g.则alter system set user_diagnostic_dest = 'd:\oracle\trace';(注意:trace文件不会直接生成在trace目录下.trace目录下会生成其他很多目录.
trace文件的具体目录是:d:\oracle\trace\diag\rdbms\orli11r2\orli11r2\trace.其中的orli11r2是SID)
4.怎么查看trace文件:
如果直接看trace文件是很难看懂的.就是下面的样子(我只是随便复制一段):
1319423003070764
=====================
PARSING IN CURSOR #2 len=90 dep=1 uid=0 oct=3 lid=0 tim=1319423003070864 hv=673844243 ad='7ecb9458' sqlid='9g485acn2n30m'
select col#,intcol#,reftyp,stabid,expctoid from refcon$ where obj#=:1 order by intcol# asc
END OF STMTPARSE #2:c=0,e=56,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,plh=2544153582,tim=1319423003070864
BINDS #2: Bind#0oacdty=02 mxl=22(22) mxlc=00 mal=00 scl=00 pre=00
oacflg=08 fl2=0001 frm=00 csi=00 siz=24 off=0 kxs
我们可以用oracle自带的工具TKPROF转化后再查看trace文件.转化后是下面的样子:
SQL ID : 0zzk39z279q41
SELECT version FROM product_component_version WHERE product LIKE 'Oracle%'
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.00 0 0 0 1
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 3 0.00 0.00 0 0 0 1
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 69
Rows Row Source Operation
------- ---------------------------------------------------
1 VIEW PRODUCT_COMPONENT_VERSION (cr=0 pr=0 pw=0 time=0 us cost=2 size=168 card=2)
1 SORT UNIQUE (cr=0 pr=0 pw=0 time=0 us cost=2 size=110 card=2)
1 UNION-ALL (cr=0 pr=0 pw=0 time=0 us)
0 FIXED TABLE FULL X$VERSION (cr=0 pr=0 pw=0 time=0 us cost=0 size=55 card=1)
1 FIXED TABLE FULL X$VERSION (cr=0 pr=0 pw=0 time=0 us cost=0 size=55 card=1)
********************************************************************************
Oracle查看trace文件步骤
1.获得当前trace文件生成路径
SQL> select tracefile from v$process where addr in (select paddr from v$session where sid in (select sid from v$mystat));
----------------------------------------------------------------------------------
f:\oracle\administrator\diag\rdbms\orcl\orcl\trace\orcl_ora_1160.trc
2.开启当前session的trace
SQL> alter session set sql_trace=true;
SQL> select count(*) from t1;
3.转换trc文件内容为可读的输出结果
注意Oracle的命令一般末尾都不要带分号。除非写的是SQL语句。否则那个分号也会算进命令里面。当做命令的内容来执行。
C:\Documents and Settings\Administrator>tkprof f:\oracle\administrator\diag\rdbms\orcl\orcl\trace\orcl_ora_1160.trc output=c:\aa.txt
TKPROF: Release 11.2.0.1.0 - Development on 星期六 10月 6 23:51:07 2012
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
4.打开c:\aa.txt, 就会看到关于SQL语句 'select count(*) from t1;' 的执行计划
[sql]
********************************************************************************
SQL ID: 5bc0v4my7dvr5
Plan Hash: 3724264953
select count(*) from t1
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.04 0 1 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 2 0.03 0.01 0 1070 0 1
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 4 0.03 0.06 0 1071 0 1
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 91
Rows Row Source Operation
------- ---------------------------------------------------
1 SORT AGGREGATE (cr=1070 pr=0 pw=0 time=0 us)
72597 TABLE ACCESS FULL T1 (cr=1070 pr=0 pw=0 time=172543 us cost=298 size=0 card=66014)
********************************************************************************
[img]http://dl2.iteye.com/upload/attachment/0094/0115/168f1a99-8cf4-3101-8e89-a623b3e3e6c2.jpg[/img]
比如我本机上的内容是：
SQL> select tracefile from v$process where addr in (select paddr from v$session where sid in (select sid from v$mystat));
TRACEFILE
----------------------------------------------------------------------------
e:\app\administrator\diag\rdbms\fsyd\fsyd\trace\fsyd_ora_8096.trc
C:\Documents and Settings\kington>tkprof e:\app\administrator\diag\rdbms\fsyd\fsyd\trace\fsyd_ora_8096.trc output=C:\fsyd_ora_8096.txt;
TKPROF: Release 11.1.0.6.0 - Production on 星期三 2月 19 18:54:13 2014
Copyright (c) 1982, 2007, Oracle. All rights reserved.
C:\Documents and Settings\kington>
转换后的 fsyd_ora_8096.txt 内容如下：
[img]http://dl2.iteye.com/upload/attachment/0094/0117/66ee3894-6d8e-3087-ba1c-98e2fb6d524a.jpg[/img]
TKPROF: Release 11.1.0.6.0 - Production on 星期三 2月 19 18:54:13 2014
Copyright (c) 1982, 2007, Oracle. All rights reserved.
Trace file: e:\app\administrator\diag\rdbms\fsyd\fsyd\trace\fsyd_ora_8096.trc
Sort options: default
********************************************************************************
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
********************************************************************************
Trace file: e:\app\administrator\diag\rdbms\fsyd\fsyd\trace\fsyd_ora_8096.trc
Trace file compatibility: 11.01.00
Sort options: default
1 session in tracefile.
0 user SQL statements in trace file.
0 internal SQL statements in trace file.
0 SQL statements in trace file.
0 unique SQL statements in trace file.
116 lines in trace file.
0 elapsed seconds in trace file.