OGG需要force logging吗？

riverchild

疑问1：从OGG的官方文档，找不到force logging这些字眼，所以怀疑是否有必要force logging.
我用sqlldr带direct=true将数据弄到source database中，但发现数据也replicat到target database.
疑问2：
Forced logging
---------------
When ever unrecoverable or nologging changes are performed, the changes are logged in the redo logfiles but invalidation
redo are generated against the data blocks involved in the changes.
有哪些操作属于unrecoverable？
有哪些操作属于nologging operations？

Thanks,
上海-ccc

Maclean Liu(刘相兵

一般 不需要force logging ，默认即可；见下表<br><br><p>以下是针对表处于logging或者no logging模式的测试结果： <br></p><p><br></p>
<table border="1" cellpadding="0" cellspacing="0" width="555">
  <tbody><tr>
    <td colspan="2" width="158"><br>
        <strong>条目</strong><strong> </strong> </td>
    <td width="113"><p align="center"><strong>logging mode</strong></p></td>
    <td valign="top" width="104"><p align="center"><strong>No logging mode</strong></p></td>
    <td width="180"><p align="center"><strong>No logging mode + Force Logging</strong></p></td>
  </tr>
  <tr>
    <td colspan="2" width="158"><p align="center">insert /*+ append */</p></td>
    <td width="113"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="104"><p align="center">Failed</p></td>
    <td valign="top" width="180"><p><strong>OK</strong></p></td>
  </tr>
  <tr>
    <td colspan="2" width="158"><p align="center">Exp direct=y / imp</p></td>
    <td width="113"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="104"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="180"><p>&nbsp;</p></td>
  </tr>
  <tr>
    <td rowspan="2" width="64"><p align="center">Sqlldr</p></td>
    <td width="94"><p align="center">direct    = true</p></td>
    <td width="113"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="104"><p align="center">Failed</p></td>
    <td valign="top" width="180"><p><strong>OK</strong></p></td>
  </tr>
  <tr>
    <td width="94"><p align="center">direct    = false</p></td>
    <td width="113"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="104"><p align="center"><strong>OK</strong></p></td>
    <td valign="top" width="180"><p>&nbsp;</p></td>
  </tr>
</tbody></table>
<p><br></p><p>由此可见，在logging  mode下各种操作均可以支持，而no logging模式则会出现问题。如果打开数据库force logging则可以捕捉到（目前尚未有官方说明）。</p>

riverchild

Thanks    .