User guide

On some systems where the workload is heavy and particularly on single-cpu systems it is
possible that after the sub-process is created the main process may attempt to establish the
communication unsuccessfully. Depending on process and thread scheduling it is possible
that the maximum number of attempts to establish handshake may occur before the sub-
process is scheduled for execution.
On these systems you may wish to increase the number of attempts at handshake or the
duration to wait between handshake attempts to prevent the premature aborting of the driver-
executor connection. You may use the handshakeTries and handshakeWait options on the
connection string to change these values.
See Connection Options
for more details.
Contents
8.6 FetchSize
The SetFetchSize methods in Statement and ResultSet allow you to set the record fetch size
for server record retrieval. The FetchSize gives a hint to the server as to how many records to
batch up and send over the network at one time.
Network I/O is very expensive, so the more data you can send in a single I/O the better the
performance. If you do not explicitly change the default FetchSize by using the FetchSize
option, the default is 100.
8.7 Ignoring Statement.cancel() Method Calls
Currently the method Statement.cancel() is not supported in the Oracle JDBC for Rdb
drivers. If an application calls this method the driver will raise the following Exception:
oracle.rdb.jdbc.common.RdbException: Unsupported feature
<Statement.cancel>
In applications and application servers that expect this feature to be present, the raising of
this exception may cause problems with the application functionality or may lead to
excessive messages being written to the application log file.
If your application does not depend on the statement cancellation to actually take effect, and
that failure to cancel can be safely ignored, you may specify the ignoreStatementCancel
switch of the connection URL:
Connection conn = DriverManager.getConnection(
113