JDBC 技术论坛

来自: yadav_kamal@hotmail.com 15-Jul-03 08:07
主题: ERROR:maximum cursor open


ERROR:maximum cursor open 

Hi All

I am working with oracle8.1.7 with tomcat 4.0.4 server .when i run application and save particular form then after save
i am getting maximum cursor open error and oracle is not respond then server might be restart again for application.
pls reply as soon as.

Thanks
Kamal yadav

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来自: Oracle, kiranmai Lang 15-Jul-03 17:10
主题: Re : ERROR:maximum cursor open

Problem Description
-------------------

You have a JDBC application which runs for several hours. It then
returns the following error:

ORA-1000 Maximum open cursors exceeded

The open_cursors parameter in init.ora is currently set to a number in
excess of the maximum number of cursors you expect your application
to have open at any one time. Increasing open_cursors extends the
period of time before failure, but does not resolve the issue.


Solution Description
--------------------

Typically, in Java, when an object goes out of scope, it is automatically garbage collected, but the Java specification does not place any specific requirements on the JVM regarding when (or even if) this will occur for any particular object. Therefore, do not rely on finalizers to close your cursors.

Explicity close all cursors ResultSet.close(), Statement.close(), and
PreparedStatement.close() when you no longer need the cursor. This ensures that the corresponding server-side cursors are closed, preventing the ORA-1000 error. Be sure to close these JDBC objects within the scope that they were created. Closing these objects in a finally{} block is recommended, however, DO NOT rely upon a finalize() method because a finalize() method is never guaranteed to run by the JVM!

A common error occurs when CallableStatement is used to call a PL/SQL procedure that returns a REF CURSOR. If you do not close the corresponding ResultSet object,a cursor will be left open on the server.

You can query the SQL_TEXT column in V$OPEN_CURSOR view from the schema to determine which cursors are not being closed. For example:

select   sql_text   from   v$open_cursor;

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