JDBC Type 2 Driver Programmer's Reference for SQL/MX Release 3.2.1 (H06.26+, J06.15+)

• JDBC/MX driver assumes that any SQL CONTROL statements in effect at the time of execution
or reuse are the same as those in effect at the time of SQL/MX compilation. If this condition
is not true, reuse of a PreparedStatement object might result in unexpected behavior.
• You should avoid SQL/MX recompilation to yield performance improvements from statement
pooling. The SQL/MX executor automatically recompiles queries when certain conditions are
met. Some of these conditions are:
◦ A run-time version of a table has a different redefinition timestamp than the compile-time
version of the same table.
◦ An existing open operation on a table was eliminated by a DDL or SQL utility operation.
◦ The transaction isolation level and access mode at execution time is different from that
at the compile time.
For more information on SQL/MX recompilation, see the SQL/MX Programming Manual for
C and COBOL or the SQL/MX Programming Manual for Java.
• When a query is recompiled, the SQL/MX executor stores the recompiled query; therefore,
the query is recompiled only once until any of the previous conditions are met again.
• JDBC/MX driver pools the CallableStatement objects in the same way as
PreparedStatement objects when the statement pooling is activated.
• JDBC/MX driver does not cache Statement objects.
Using Additional JDBC/MX Properties
You can use JDBC/MX properties for the following application features:
• “BatchUpdate Exception handling Improvements” (page 39)
• “Statement Level Atomicity” (page 40)
• “Managing Nonblocking JDBC/MX” (page 40)
• “Setting Batch Processing for Prepared Statements” (page 41)
• “Setting the reserveDataLocators Property” (page 42)
In addition to these topics, also see “Enabling Tracing for Application Servers” (page 76).
BatchUpdate Exception handling Improvements
When a command in the batch fails, the remaining commands of the batch are not executed
resulting in re-execution of entire batch. But, with this Batch Update Exception handling support,
the remaining elements of the batch after the error prone statement can be executed and hence
re-execution of the entire batch jobs can be avoided.
contBatchOnError property
The contBatchOnError property communicates with JDBC driver to continue the remaining jobs in
the batch even after any BatchUpdateExceptions. This java property can be set from the command
line as:
Djdbcmx.contBatchOnError={ON|OFF}
where
ON
continues batch execution even after any other batch exception
OFF
terminates the batch execution on any other batch exception. The default is set to
OFF.
Using Additional JDBC/MX Properties 39