小议OracleRESET参数

小议OracleRESET参数    本来RESET语法比较简单，结果被
[url=http://oracle.chinaitlab.com/][color=#2f5fa1]Oracle[/color][/url]
的文档上的错误信息彻底搞晕了，测试了半天才明白。

    无论是
[url=http://oracle.chinaitlab.com/][color=#2f5fa1]Oracle[/color][/url]
920的RAC 管理文档还是Oracle 1020的RAC管理和部署文档，在设置SPFILE部分都有错误。而且不光是给出的SQL语句有问题，很多描述本身就是错误的。

    由于错误实在太多，这里就不详细描述了。如果看到Oracle文档中的这部分内容，需要小心注意一下。

    ALTER SYSTEM RESET语句用于撤销SPFILE中错误的参数设置。无论单实例系统还是RAC环境都是可以使用的。为了描述的简单，下面的例子使用了单实例环境，而单实例和RAC环境没有什么本质的区别。

    RESET的使用需要注意以下几点：

    使用RESET时，必须指定SID，否则会出现错误。



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SQL> ALTER SYSTEM RESET OPEN_CURSORS;

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ALTER SYSTEM RESET OPEN_CURSORS

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*第 1 行出现错误:

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ORA-00905: 缺失关键字

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SQL> ALTER SYSTEM RESET OPEN_CURSORS SCOPE = SPFILE;

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ALTER SYSTEM RESET OPEN_CURSORS SCOPE = SPFILE

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*第 1 行出现错误:

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ORA-00905: 缺失关键字

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    不管是SET语句还是RESET语句，必须先指定SCOPE，然后指定SID语句，二者顺序不可颠倒。
  


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SQL> ALTER SYSTEM SET OPEN_CURSORS = 300;

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系统已更改。

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SQL> ALTER SYSTEM RESET OPEN_CURSORS SID = '*' SCOPE = SPFILE;

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ALTER SYSTEM RESET OPEN_CURSORS SID = '*' SCOPE = SPFILE

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*第 1 行出现错误:

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ORA-00933: SQL 命令未正确结束

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SQL> ALTER SYSTEM SET OPEN_CURSORS = 500 SID = '*' SCOPE = SPFILE;

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ALTER SYSTEM SET OPEN_CURSORS = 500 SID = '*' SCOPE = SPFILE

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*第 1 行出现错误:

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ORA-02065: 非法的 ALTER SYSTEM 选项

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    RESET语句中，如果SCOPE指定MEMORY或BOTH的时候，SID不能为‘*’。
  


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SQL> ALTER SYSTEM RESET OPEN_CURSORS SCOPE = MEMORY SID = '*';

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ALTER SYSTEM RESET OPEN_CURSORS SCOPE = MEMORY SID = '*'

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*第 1 行出现错误:

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ORA-32009: 无法重置实例 * 的内存值 (从实例 ytk 中)

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SQL> ALTER SYSTEM RESET OPEN_CURSORS SID = '*';

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ALTER SYSTEM RESET OPEN_CURSORS SID = '*'

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