Performance Considerations

The following connection options can enhance driver performance. You can also enhance performance through efficient application design. Refer to "Designing ODBC Applications for Performance Optimization" in the DataDirect Connect for ODBC and Connect XE for ODBC Reference for details.

The option names found on the tabs of the driver Setup dialog box are the same as the connection string attribute names unless otherwise noted in parentheses. The connection string attribute name does not have spaces between the words. For example, the option name Application Using Threads is equivalent to the connection string attribute name ApplicationUsingThreads.

Use Snapshot Transactions (SnapshotSerializable): You must have your Microsoft SQL Server 2005 database configured for snapshot isolation for this connection option to work. See "Isolation and Lock Levels Supported" for details.

Snapshot Isolation provides transaction-level read consistency and an optimistic approach to data modifications by not acquiring locks on data until data is to be modified. This Microsoft SQL Server 2005 feature can be useful if you want to consistently return the same result set even if another transaction has changed the data and 1) your application executes many read operations or 2) your application has long running transactions that could potentially block users from reading data. This feature has the potential to eliminate data contention between read operations and update operations. When this connection option is enabled, performance is improved due to increased concurrency.