隐式参数_trace_files_public决定了Oracle产生的trace文件是否公开,该参数默认值为FALSE,也就是非DBA/OINSTALL组的用户是没有权限读取数据库产生的trace文件的;在某些场合中我们需要让非DBA组的用户也能访问trace文件,就可以通过修改该参数实现。请看下面的例子:
<a href="http://blog.51cto.com/maclean/1277527#">?</a>
<code>SQL> </code><code>select</code> <code>* </code><code>from</code> <code>v$version;</code>
<code>BANNER</code>
<code>----------------------------------------------------------------</code>
<code>Oracle </code><code>Database</code> <code>10g Enterprise Edition Release 10.2.0.4.0 - 64bi</code>
<code>PL/SQL Release 10.2.0.4.0 - Production</code>
<code>CORE 10.2.0.4.0 Production</code>
<code>TNS </code><code>for</code> <code>Linux: Version 10.2.0.4.0 - Production</code>
<code>NLSRTL Version 10.2.0.4.0 - Production</code>
<code>SQL> col </code><code>name</code> <code>for</code> <code>a20</code>
<code>SQL> col value </code><code>for</code> <code>a20</code>
<code>SQL> col describ </code><code>for</code> <code>a40</code>
<code>SQL> </code><code>SELECT</code> <code>x.ksppinm </code><code>NAME</code><code>, y.ksppstvl VALUE, x.ksppdesc describ</code>
<code> </code><code>2 </code><code>FROM</code> <code>SYS.x$ksppi x, SYS.x$ksppcv y</code>
<code> </code><code>3 </code><code>WHERE</code> <code>x.inst_id = USERENV (</code><code>'Instance'</code><code>)</code>
<code> </code><code>4 </code><code>AND</code> <code>y.inst_id = USERENV (</code><code>'Instance'</code><code>)</code>
<code> </code><code>5 </code><code>AND</code> <code>x.indx = y.indx</code>
<code> </code><code>6 </code><code>AND</code> <code>x.ksppinm </code><code>LIKE</code> <code>'%_trace_files_public%'</code>
<code> </code><code>7 </code><code>order</code> <code>by</code> <code>x.ksppinm;</code>
<code>NAME</code> <code>VALUE DESCRIB</code>
<code>-------------------- -------------------- ----------------------------------------</code>
<code>_trace_files_public </code><code>FALSE</code> <code>Create</code> <code>publicly accessible trace files</code>
<code>SQL> oradebug setmypid;</code>
<code>Statement processed.</code>
<code>SQL> oradebug ipc;</code>
<code>Information written </code><code>to</code> <code>trace file.</code>
<code>SQL> oradebug tracefile_name;</code>
<code>/s01/10gdb/admin/YOUYUS/udump/youyus_ora_10268.trc</code>
<code>SQL> !ls -l /s01/10gdb/admin/YOUYUS/udump/youyus_ora_10268.trc</code>
<code>-rw-r</code><code>----- 1 maclean oinstall 4206 Aug 11 20:51 /s01/10gdb/admin/YOUYUS/udump/youyus_ora_10268.trc</code>
<code>/*所产生的trace文件权限为640,非oinstall组用户无权限读取该文件*/</code>
<code>SQL> </code><code>alter</code> <code>system </code><code>set</code> <code>"_trace_files_public"</code><code>=</code><code>true</code><code>;</code>
<code>alter</code> <code>system </code><code>set</code> <code>"_trace_files_public"</code><code>=</code><code>true</code>
<code> </code><code>*</code>
<code>ERROR </code><code>at</code> <code>line 1:</code>
<code>ORA-02095: specified initialization parameter cannot be modified</code>
<code>/*修改该参数需要重启实例*/</code>
<code>SQL> </code><code>alter</code> <code>system </code><code>set</code> <code>"_trace_files_public"</code><code>=</code><code>true</code> <code>scope=spfile;</code>
<code>System altered.</code>
<code>SQL> startup </code><code>force</code><code>;</code>
<code>ORACLE instance started.</code>
<code>Total System </code><code>Global</code> <code>Area 1577058304 bytes</code>
<code>Fixed </code><code>Size</code> <code>2084264 bytes</code>
<code>Variable </code><code>Size</code> <code>922747480 bytes</code>
<code>Database</code> <code>Buffers 637534208 bytes</code>
<code>Redo Buffers 14692352 bytes</code>
<code>Database</code> <code>mounted.</code>
<code>Database</code> <code>opened.</code>
<code>/s01/10gdb/admin/YOUYUS/udump/youyus_ora_10430.trc</code>
<code>SQL> ! ls -l /s01/10gdb/admin/YOUYUS/udump/youyus_ora_10430.trc</code>
<code>-rw-r</code><code>--r-- 1 maclean oinstall 5471 Aug 11 20:54 /s01/10gdb/admin/YOUYUS/udump/youyus_ora_10430.trc</code>
<code>/*other组用户也具有了读权限*/</code>
<code>SQL> ! ls -l /s01/10gdb/admin/YOUYUS/</code>
<code>total 24</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 11 20:56 adump</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 11 20:54 bdump</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 5 21:35 cdump</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 5 21:36 dpdump</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 5 21:37 pfile</code>
<code>drwxr-x</code><code>--- 2 maclean oinstall 4096 Aug 11 20:54 udump</code>
<code>/*请注意修改_trace_files_public为</code><code>true</code><code>,并不会修改trace所在目录的权限,Oracle默认建立bdump/udump等trace目录时分配的权限为750,other组用户无法进入这些目录,需要修改目录权限为755,即o+r+x*/</code>
<code>SQL> ! chmod o+r+x /s01/10gdb/admin/YOUYUS/*dump</code>
<code>SQL> ! ls -l /s01/10gdb/admin/YOUYUS/</code>
<code>drwxr-xr-x 2 maclean oinstall 4096 Aug 11 20:56 adump</code>
<code>drwxr-xr-x 2 maclean oinstall 4096 Aug 11 20:54 bdump</code>
<code>drwxr-xr-x 2 maclean oinstall 4096 Aug 5 21:35 cdump</code>
<code>drwxr-xr-x 2 maclean oinstall 4096 Aug 5 21:36 dpdump</code>
<code>drwxr-xr-x 2 maclean oinstall 4096 Aug 11 20:54 udump</code>
<code>/*需要注意的另一点是修改_trace_files_public参数并不会引起既有的trace文件的权限被修改,典型的例子是alert log告警日志*/</code>
<code>[maclean@rh2 bdump]$ ls -l</code>
<code>total 20</code>
<code>-rw-r</code><code>----- 1 maclean oinstall 12971 Aug 11 21:17 alert_YOUYUS.log</code>
<code>-rw-r</code><code>--r-- 1 maclean oinstall 690 Aug 11 21:12 youyus_lgwr_10514.trc</code>
<code>SQL> !ls -l</code>
<code>total 32</code>
<code>-rw-r</code><code>----- 1 maclean oinstall 21189 Aug 11 21:20 alert_YOUYUS.log</code>
<code>-rw-r</code><code>--r-- 1 maclean oinstall 690 Aug 11 21:20 youyus_lgwr_11136.trc</code>
本文转自maclean_007 51CTO博客,原文链接:http://blog.51cto.com/maclean/1277527