JDBC Type 2 Driver 3.0 Programmer's Reference (SQL/MX 3.x)

JDBC/MX driver to use more memory, but does not affect the API's functionality.
Troubleshooting Statement Pooling
Note the following JDBC/MX driver implementation details if you are troubleshooting statement pooling:
JDBC/MX driver looks for a matching PreparedStatement object in the statement pool and reuses the
PreparedStatement. The matching criteria include the SQL string, current catalog, current schema,
current transaction isolation, and
resultSetHoldability. If JDBC/MX driver finds the matching
PreparedStatement object, JDBC/MX driver returns the same preparedStatement object to the
application for reuse and marks the
PreparedStatement object as in use.
The algorithm, "earlier used are the first to go," is used to make room for caching subsequently
generated
PreparedStatement objects when the number of statements reaches the maxStatements
limit.
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
Statement Level Atomicity
Managing Nonblocking JDBC/MX
Setting Batch Processing for Prepared Statements
Setting the reserveDataLocators Property
In addition to these topics, also see Enabling Tracing for Application Servers.
BatchUpdate Exception handling Improvements