ch1_admin.htm

Debian中文参考手册,系统介绍了Debian系统

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<strong>Note:</strong>
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</p>Shut down all executables that are running in the ORACLE&#095;HOME that you are relinking, including the listener and Oracle Intelligent Agent. In addition, shut down any applications that are linked with any Oracle shared libraries.
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<p>The relink script manually relinks Oracle product executables, depending on the products that have been installed in the Oracle home directory.
</p>
<p>To relink product executables, enter the following command, where <em><code>argument</code></em> is one of the values listed in <a href="#g95310">Table 1-3</a>:
</p>
<p><code>&#036; relink </code><em><code>argument</code></em>
</p><a id="sthref131" name="sthref131"></a><a id="g95310" name="g95310"></a>
<p><strong><em><font face="arial, helvetica, sans-serif">Table 1-3 Relink Script Parameters 
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<table title="Relink Script Parameters " summary="Table listing the relink script parameters." dir="ltr" border="1" width="100%" frame="hsides" rules="groups" cellpadding="3" cellspacing="0">
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<tr align="left" valign="top">
<th id="r1c1" align="left" colspan="1" rowspan="1" valign="bottom">
<font face="Arial, Helvetica, sans-serif">
<strong>Value
</strong></font></th>
<th id="r1c2" align="left" colspan="1" rowspan="1" valign="bottom">
<font face="Arial, Helvetica, sans-serif">
<strong>Description
</strong></font></th>
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</thead><tbody>
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<td id="r2c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>all</code>
</td>
<td headers="r2c1 r1c2" align="left" colspan="1" rowspan="1">Every product executable that has been installed
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<td id="r3c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>oracle</code>
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<td headers="r3c1 r1c2" align="left" colspan="1" rowspan="1">Oracle server executable only
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<td id="r4c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>network</code>
</td>
<td headers="r4c1 r1c2" align="left" colspan="1" rowspan="1"><code>net&#095;client</code>, <code>net&#095;server</code>, <code>cman</code>, <code>names</code>
</td>
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<td id="r5c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>client</code>
</td>
<td headers="r5c1 r1c2" align="left" colspan="1" rowspan="1"><code>net&#095;client</code>, <code>otrace</code>, <code>plsql</code>
</td>
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<td id="r6c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>ctx</code>
</td>
<td headers="r6c1 r1c2" align="left" colspan="1" rowspan="1">Oracle Text utilities
</td>
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<td id="r7c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>precomp</code>
</td>
<td headers="r7c1 r1c2" align="left" colspan="1" rowspan="1">All precompilers that have been installed
</td>
</tr>
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<td id="r8c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>utilities</code>
</td>
<td headers="r8c1 r1c2" align="left" colspan="1" rowspan="1">All utilities that have been installed
</td>
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<td id="r9c1" headers="r1c1" align="left" colspan="1" rowspan="1"><code>oemagent</code>
</td>
<td headers="r9c1 r1c2" align="left" colspan="1" rowspan="1"><code>oemagent</code>
<p><strong>Note:</strong> To give the correct permissions to the <code>dbsnmp</code> executable, you must run the <code>root.sh</code> script after relinking <code>oemagent</code> executables.
</p>
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<td id="r10c1" headers="r1c1" align="left" colspan="1" rowspan="1">ldap
</td>
<td headers="r10c1 r1c2" align="left" colspan="1" rowspan="1"><code>ldap</code>, <code>oid</code>
</td>
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</table>
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<font face="arial, helvetica, sans-serif" color="#330099">System Global Area<a id="sthref133" name="sthref133"></a>
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<p>The System Global Area (SGA) is the Oracle structure that is located in shared memory. It contains static data structures, locks, and data buffers. Sufficient shared memory must be available to each Oracle process to address the entire SGA.
</p>
<p>The maximum size of a single shared memory segment is specified by the SHMMAX<a id="sthref134" name="sthref134"></a><a id="sthref135" name="sthref135"></a><a id="sthref136" name="sthref136"></a><a id="sthref137" name="sthref137"></a> kernel parameter (SHM&#095;MAX on Tru64). The following table shows the recommended value for this parameter, depending on your platform:
</p>
<table title="SHMMAX Parameter Values" summary="Table listing the recommened values for the SHMMAX kernel parameter by platform." dir="ltr" border="1" width="100%" frame="hsides" rules="groups" cellpadding="3" cellspacing="0">
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<th id="r1c1" align="left" colspan="1" rowspan="1" valign="bottom">
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<strong>Platform
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<th id="r1c2" align="left" colspan="1" rowspan="1" valign="bottom">
<font face="Arial, Helvetica, sans-serif">
<strong>Recommended Value
</strong></font></th>
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</thead><tbody>
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<td id="r2c1" headers="r1c1" align="left" colspan="1" rowspan="1">AIX
</td>
<td headers="r2c1 r1c2" align="left" colspan="1" rowspan="1">Not applicable.
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<td id="r3c1" headers="r1c1" align="left" colspan="1" rowspan="1">HP
</td>
<td headers="r3c1 r1c2" align="left" colspan="1" rowspan="1">The size of the physical memory installed on the system.
<p><strong>See Also:</strong> <a href="appb_hp.htm#CHDGJCIB">"HP-UX Shared Memory Segments for a 64-Bit Oracle Instance "</a>  for information on the SHMMAX parameter on HP.
</p>
</td>
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<td id="r4c1" headers="r1c1" align="left" colspan="1" rowspan="1">Solaris
</td>
<td headers="r4c1 r1c2" align="left" colspan="1" rowspan="1">4 GB minus 16 MB. Can be greater than 4 GB on 64-bit systems.
</td>
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<td id="r5c1" headers="r1c1" align="left" colspan="1" rowspan="1">Tru64
</td>
<td headers="r5c1 r1c2" align="left" colspan="1" rowspan="1">4 GB minus 16 MB.
<p><strong>Note:</strong> The value of the SHM&#095;MAX parameter must be at least 16 MB for the Oracle instance to start. If your system runs both Oracle8<em>i</em> and Oracle9<em>i</em> instances, you must set the value of this parameter to 2 GB minus 16 MB.
</p>
</td>
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<td id="r6c1" headers="r1c1" align="left" colspan="1" rowspan="1">Linux
</td>
<td headers="r6c1 r1c2" align="left" colspan="1" rowspan="1">Half the size of the physical memory installed on the system.
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</table>
<p>If the size of the SGA exceeds the maximum size of a shared memory segment (SHMMAX or SHM&#095;MAX), Oracle9<em>i</em> attempts to attach more contiguous segments to fulfill the requested SGA size. The SHMSEG<a id="sthref138" name="sthref138"></a><a id="sthref139" name="sthref139"></a><a id="sthref140" name="sthref140"></a><a id="sthref141" name="sthref141"></a> kernel parameter (SHM&#095;SEG on Tru64) specifies the maximum number of segments that can be attached by any process. 
</p><a id="i71057" name="i71057"></a>
<p>Set the following initialization file parameters to control the size of the SGA:
</p>
<ul>
<li type="disc">
<p>DB&#095;CACHE&#095;SIZE<a id="sthref142" name="sthref142"></a><a id="sthref143" name="sthref143"></a><a id="sthref144" name="sthref144"></a><a id="sthref145" name="sthref145"></a>
</p>
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<p>DB&#095;BLOCK&#095;SIZE<a id="sthref146" name="sthref146"></a><a id="sthref147" name="sthref147"></a><a id="sthref148" name="sthref148"></a><a id="sthref149" name="sthref149"></a>
</p>
</li>
<li type="disc">
<p>JAVA&#095;POOL&#095;SIZE<a id="sthref150" name="sthref150"></a><a id="sthref151" name="sthref151"></a>
</p>
</li>
<li type="disc">
<p>LARGE&#095;POOL&#095;SIZE<a id="sthref152" name="sthref152"></a><a id="sthref153" name="sthref153"></a>
</p>
</li>
<li type="disc">
<p>LOG&#095;BUFFERS<a id="sthref154" name="sthref154"></a><a id="sthref155" name="sthref155"></a>
</p>
</li>
<li type="disc">
<p>SHARED&#095;POOL&#095;SIZE<a id="sthref156" name="sthref156"></a><a id="sthref157" name="sthref157"></a>
</p>
</li>
</ul>
<p>Use caution when setting values for these parameters. When values are set too high, too much of the computer&#039;s physical memory is devoted to shared memory, resulting in poor performance.
</p>
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Determining the Size of the SGA<a id="sthref159" name="sthref159"></a>
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</h3>
<p>You can determine the SGA size in one of the following ways:
</p>
<ul>
<li type="disc">
<p>Enter the following SQL&#042;Plus command to display the size of the SGA for a running database:
</p>
<pre>SQL&gt; SHOW SGA

</pre>
<p>The result is shown in bytes.
</p>
</li>
<li type="disc">
<p>Determine the size of the SGA when you start your database instance. The SGA size is displayed next to the heading Total System Global Area.
</p>
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Intimate Shared Memory (Solaris Only)<a id="sthref161" name="sthref161"></a>
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<p>On Solaris systems, Oracle9<em>i</em> uses Intimate Shared Memory (ISM) for shared memory segments because it shares virtual memory resources among Oracle processes. On Solaris 2.6 and Solaris 7, Oracle9<em>i</em> uses ISM by default. ISM causes the physical memory for the entire shared memory segment to be locked automatically.
</p>
<p>On Solaris 8, dynamic&#047;pageable ISM (DISM) is available. This enables Oracle9<em>i</em> to share virtual memory resources among processes sharing the segment, and at the same time, enables memory paging. The operating system does not have to lock down physical memory for the entire shared memory segment. 
</p>
<p>Oracle9<em>i</em> automatically decides at startup whether to use ISM or DISM, based on the following criteria:
</p>
<ul>
<li type="disc">
<p>Oracle9<em>i</em> uses DISM<a id="sthref162" name="sthref162"></a><a id="sthref163" name="sthref163"></a> if it is available on the system, and if the value of the SGA&#095;MAX&#095;SIZE<a id="sthref164" name="sthref164"></a><a id="sthref165" name="sthref165"></a> initialization parameter is larger than the size required for all SGA components combined. This allows Oracle9<em>i</em> to lock only the amount of physical memory that is used. 
</p>
</li>
<li type="disc">
<p>Oracle9<em>i</em><em> </em>uses ISM if the entire shared memory segment is in use at startup or if the value of the SGA&#095;MAX&#095;SIZE parameter is equal to or smaller than the size required for all SGA components combined. 
</p>
</li>
</ul>
<p>Regardless of whether Oracle9<em>i</em> uses ISM or DISM, it can always exchange the memory between dynamically sizable components such as the buffer cache, the shared pool, and the large pool after it starts an instance. Oracle9<em>i</em> can relinquish memory from one dynamic SGA component and allocate it to another component. 
</p>
<p>Because shared memory segments are not implicitly locked in memory, when using DISM, Oracle9<em>i</em> explicitly locks shared memory that is currently in use at startup. When a dynamic SGA operation uses more shared memory, Oracle9<em>i</em> explicitly performs a lock operation on the memory that comes in use. When a dynamic SGA operation releases shared memory, Oracle9<em>i</em> explicitly performs an unlock operation on the memory that is freed, so that it becomes available to other applications. 
</p>
<p>Oracle9<em>i</em> uses a new utility, <code>oradism<a id="sthref166" name="sthref166"></a></code>, to lock and unlock shared memory. If the LOCK&#095;SGA parameter is set to TRUE, Oracle9<em>i</em> attempts to lock the entire SGA at startup. In this case, no locks or unlocks are performed when the SGA resizes.
</p>
<p>With Oracle9<em>i</em> release 2 (9.2.0.1.0), the <code>oradism</code> utility is automatically set up during installation. You do not need to perform any configuration tasks to use dynamic SGA.
</p>
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<br /><table summary="This is a layout table to format a note" title="This is a layout table to format a note" dir="ltr" border="1" width="80%" frame="hsides" rules="groups" cellpadding="3" cellspacing="0"><tbody>
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<strong>Note:</strong>
</font>
</p>The process name for the <code>oradism</code> utility is <code>ora&#095;dism&#095;</code><em><code>sid</code></em>, where <em><code>sid</code></em> is the system identifier. When using DISM, this process is started during instance startup, and automatically quits when the instance is shut down.If a message appears in the alert log saying that the <code>oradism</code> utility is not set up correctly, verify that the <code>oradism</code> utility is located in the <code>&#036;ORACLE&#095;HOME&#047;bin&#047;</code> directory and that it has superuser privileges.
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