Am I right? But from 9. Could you please tell me the new meaning of this parameter? Thanks Chandan. April 30, - pm UTC. The size of that cache is limited by this parameter. It controls the size of the plsql cursor cache and the client "softer soft parse" cache - neither of which will incur the ora max open cursors exceeded.
Hi Tom, 1 As per document Could you please explain what is unparsed but opened dynamic cursors? Is it unparsed but opened dynamic cursors? Thanks chandan. May 01, - pm UTC. Maybe we can cut to the chase and give you what you need instead of going back and forth and back and forth. Hi Tom, I am having the problem of ora That's why I am trying to know the followings : 1 As per document I will be highly obliged if you kindly answer the above 2 questions with example.
I am just trying to understand properly. Tom, Thanks. Can you tell how to spot a leak? We are encountering ORA error. I think it is leak but how do we find it.
Is there some place it goes. August 13, - am UTC. Can you please guide? Best Regards Jatin. December 01, - am UTC. Easy to answer: This username has more than one session, each session has less then open cursors. In continuation to above Jatin, November 30, - pm UTC. I am not summing on username, infact it's a max value grouped by username. Could it be that we are using middle tier tuxedo for connection pooling and the above is showing a cumulative summation of connections taking over the same sid But in that case too the max limit of should raise an ora error?
Please Guide. Do you really see that many open cursors? Hi Tom There is no trace of an "alter system" command in alert log file for last 6 weeks. So, I believe that this assumption is not valid. Thanks for all the advice. Regards Jatin. December 02, - am UTC. I keep encountering ORA and can't even create a table. Here is an example from a forum:. Keep in mind when resolving ORA in this way that changing this value in the proper way should not alter the system performance, but will probably require more memory for cursor storing.
Feel free to ask questions on our Oracle forum. Verify experience! Please see if the answer is useful : stackoverflow. For tracking down open cursors in Oracle, you might also want to take a look at the SYS. Add a comment. Active Oldest Votes. Common causes are: Configuration mistake You have more threads in your application querying the database than cursors on the DB. One case is where you have a connection and thread pool larger than the number of cursors on the database.
You have many developers or applications connected to the same DB instance which will probably include many schemas and together you are using too many connections. Solution: Increasing the number of cursors on the database if resources allow or Decreasing the number of threads in the application. Cursor leak The applications is not closing ResultSets in JDBC or cursors in stored procedures on the database Solution : Cursor leaks are bugs; increasing the number of cursors on the DB simply delays the inevitable failure.
Leaks can be found using static code analysis , JDBC or application-level logging, and database monitoring. What is a cursor? Finding and setting the number of cursors The number is normally configured by the DBA on installation. A connection can have only a single transaction open at any one time but transactions can be nested A JDBC ResultSet is supported by a single cursor on the database.
When close is called on the ResultSet, the cursor is released. If you have a loop over, for example, creating and executing Statements, remember to close each Statement within the loop.
It is generally better practice to: Use object instance or class members to hold JDBC objects that are reused multiple times over a longer period, such as Connections and PreparedStatements Use local variables for ResultSets since these are obtained, looped over and then closed typically within the scope of a single function. Never store values in your own caches or static members - this is not safe across clusters and other weird conditions, and the Application Server may do terrible things to your data.
Instead use stateful beans or a database. The Application Server not only provides a connection pool, it also caches your PreparedStatements. Eliminating leaks There are a number of processes and tools available for helping detect and eliminating JDBC leaks: During development - catching bugs early is by far the best approach: Development practices: Good development practices should reduce the number of bugs in your software before it leaves the developer's desk.
Specific practices include: Pair programming , to educate those without sufficient experience Code reviews because many eyes are better than one Unit testing which means you can exercise any and all of your code base from a test tool which makes reproducing leaks trivial Use existing libraries for connection pooling rather than building your own Static Code Analysis: Use a tool like the excellent Findbugs to perform a static code analysis.
Findbugs has a plugin for Eclipse, but it also runs standalone for one-offs, has integrations into Jenkins CI and other build tools At runtime: Holdability and commit If the ResultSet holdability is ResultSet. This can be set using Connection.
Logging at runtime. Put good log statements in your code. These should be clear and understandable so the customer, support staff and teammates can understand without training. Good logging is fundamental to debugging applications, especially those that have been deployed. Counting the open and closes should highlight if there is a potential problem Monitoring the database.
Monitoring is described in this article. If the number of cursors is increasing, and most importantly becoming dominated by one identical SQL statement, you know you have a leak with that SQL. Search your code and review. Other thoughts Can you use WeakReferences to handle closing connections? Improve this answer. Community Bot 1 1 1 silver badge. Andrew Alcock Andrew Alcock If you create statements in a loop, make sure it is closed in the loop else you will end up closing only the last statement.
Thanks, basiljames. Just edited the answer to add in the point you made. Andrew Alcock Thanks a lot! Could you please answer the 6th also. AndrewAlcock Please.. Since our project we are facing ORA very frequently while load testing.
Your inputs are more valuable for me. Thanks a ton in advance!! RE: 7 - you can try proximity searching using a tool such as grep. When you recognize a SQL select, insert, update, delete , see the proximity of the word close next to the statement. If the proximity is further away than expected, that might be a way to investigate where it is missing.
Show 3 more comments. I am adding few more understanding. Cursor is only about a statement objecct; It is neither resultSet nor the connection object. But still we have to close the resultset to free some oracle memory. Closing Statement object will automatically close resultset object too. Both SID are different. So we can have many JDBC connection with its respective no of cursors statements.
Loggin as sysdba. Here is another query that seems to work well: stackoverflow. Mirko Mirko 1, 1 1 gold badge 12 12 silver badges 19 19 bronze badges. Jon Schneider Jon Schneider Hibernate has a Statement cache too. See also developer. I too had faced this issue. The below exception used to come java. Piyush Verma Piyush Verma 2 2 silver badges 7 7 bronze badges.
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