ODBC Server Installation and Management Manual

Managing the NonStop ODBC Server
HP NonStop ODBC Server Installation and Management Manual—429395-002
4-9
Configuring ODBC Datasources
Access Mode
The parameters for this option are as follows:
Cursor Default Mode
The parameters for this option are as follows:
It should be noted that there can be an advantage to using read/write mode when the
amount of time it takes for SQL/MP to return a single row is on the order of hundreds of
milliseconds or greater. In this case, individual rows are returned to the client faster in
read-write mode because the ODBC driver requests only one row at a time; the client
does not have to wait for the server to return multiple rows. Having individual rows
returned faster can be better for certain types of applications.
The best way to determine the correct setting is to experiment with these options and
select the one that gives the best overall performance.
SQL_MODE_READ_WRITE The connection is configured to support full
read/write access to the NonStop system.
SQL_MODE_READ_ONLY The connection is configured for read-only access.
Any attempt to perform a database update is
rejected with an error.
SQL_MODE_NULL The connection is configured to use the default for
the system to which you are connecting. The default
for NonStop is SQL_MODE_READ_WRITE.
FOR_UPDATE You can perform updates against a cursor.
READ_ONLY No UPDATE WHERE CURRENT OF operations
can be performed against the cursor; the driver uses
the same blocking mechanism for getting rows from
the NonStop ODBC Server as described for the
“Read-Only Standard” data access option. This
option is not related to the access mode described
previously. In particular, this option still applies even
if access mode is set to read/write.
READ_ONLY_STREAMING No UPDATE WHERE CURRENT OF operations can
be performed against the cursor; the driver uses the
same streaming mechanism for getting rows from
the NonStop ODBC Server as that for the “Read-
Only Fast Transfer” data access option. This option
is not related to the access mode described
previously. In particular, this option still applies even
if access mode is set to read/write.