- Ora 01000 maximum open cursors exceeded driver#
- Ora 01000 maximum open cursors exceeded software#
- Ora 01000 maximum open cursors exceeded code#
Ora 01000 maximum open cursors exceeded driver#
You can add a debugging JDBC driver to your project (for debugging - don't actually deploy it). Good logging is fundamental to debugging applications, especially those that have been deployed. They should be terse and include printing the state/internal values of key variables and attributes so that you can trace processing logic. These should be clear and understandable so the customer, support staff and teammates can understand without training. This can be set using tHoldability() or by using the overloaded Connection.createStatement() method.
If the ResultSet holdability is ResultSet.CLOSE_CURSORS_OVER_COMMIT, then the ResultSet is closed when the mit() method is called. Findbugs has a plugin for Eclipse, but it also runs standalone for one-offs, has integrations into Jenkins CI and other build tools This picks up many places where the close() has not been correctly handled. Ora 01000 maximum open cursors exceeded code#
Static Code Analysis: Use a tool like the excellent Findbugs to perform a static code analysis.
Use existing libraries for connection pooling rather than building your own. Unit testing which means you can exercise any and all of your code base from a test tool which makes reproducing leaks trivial. Code reviews because many eyes are better than one. Pair programming, to educate those without sufficient experience. Ora 01000 maximum open cursors exceeded software#
There are a number of processes and tools available for helping detect and eliminating JDBC leaks:ĭuring development - catching bugs early is by far the best approach:ĭevelopment practices: Good development practices should reduce the number of bugs in your software before it leaves the developer's desk. The Application Server not only provides a connection pool, it also caches your PreparedStatements.
In particular, never hold JDBC objects (Connections, ResultSets, PreparedStatements, etc) over different remote invocations - let the Application Server manage this. Instead use stateful beans or a database. 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. When saving values (state) between calls, you have to be very careful. Only the Application Server creates connections (which you obtain from the connection pool). Only the Application Server creates threads (with which it handles incoming requests). There is, however, one exception: If you are using EJBs, or a Servlet/JSP container, you have to follow a strict threading model: Use local variables for ResultSets since these are obtained, looped over and then closed typically within the scope of a single function. Use object instance or class members to hold JDBC objects that are reused multiple times over a longer period, such as Connections and PreparedStatements. JDBC objects can be safely held in local variables, object instance and class members. In Java 7, Oracle has introduced the AutoCloseable interface which replaces most of the Java 6 boilerplate with some nice syntactic sugar. If you have a loop over, for example, creating and executing Statements, remember to close each Statement within the loop. We want to allow any exception raised in the body of the try to propagate to the caller. , it might fail and prevent the Statement being closed Is it advisable to use instance variable statement/resultset object instead of method local statement/resultset object in a single threaded environment ?ĭoes executing a prepared statement in a loop cause this issue ? (Of course, I could have used sqlBatch) Note: pStmt is closed once loop is over. Is there a way to configure the number of statement/resultset objects in the database (like connections) ?. Are maximum open cursors exactly related to number of JDBC connections, or are they also related to the statement and resultset objects we have created for a single connection ? (We are using pool of connections).
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