SQL Server 2005 features
The SNC database interface supports several features that
were introduced in SQL Server 2005. For more information about using
these features, see the Microsoft SQL Server 2005 documentation.
Multiple Active Result Sets
The SNC interface supports Multiple Active Result Sets (MARS),
which enable applications to have multiple default result sets open
and to interleave reading from them. Applications can also execute
statements such as INSERT, UPDATE,
and DELETE and stored procedure calls while default
result sets are open.
Encryption without validation
SQL Server 2005 always encrypts network packets associated
with logging. If no certificate is provided on the server when it
starts up, SQL Server generates a self-signed certificate that is
used to encrypt login packets.
The SQL Native Client supports encrypting data sent to the
server without validating the certificate. The TrustServerCertificate
database parameter, available on the System page of the database
connection profile dialog box, allows you to control this feature.
Snapshot isolation
The snapshot isolation level is designed to enhance concurrency
for online transaction processing applications. Transactions that
start under snapshot isolation read a database snapshot taken at
start up time. Keyset, dynamic, and static server cursors in this
context behave like static cursors opened within serializable transactions,
but locks are not taken, which can reduce blocking on the server.
The SQLCA.Lock value for snapshot isolation is SS. You can set this
value in the Isolation Level field on the Transaction page of the
database connection profile dialog box.