This section describes the process performed by the .NET Data Provider for Teradata to make a connection to the Teradata database. Steps 1 through 8 described below must be completed in the time specified by the ConnectionTimeout. If the timer is exceeded, the connection process is terminated, and the transport layer is closed.

1. The DataSource is resolved to an IP address. See DataSource Resolution for more information.
2. The session transport is connected using the resolved IP address.  If multiple IP addresses are defined in DNS, the transport layer will attempt to connect to each IP address.
3. An initial message is sent to the Teradata Database.
4. An authentication mechanism is chosen for the Teradata session. See Authentication Mechanism Selection for more information.
5. The credentials to use for authentication are constructed if the mechanism requires credentials. See Authentication String Construction for more information.
6. A Security Context is created using TeraGSS.
7. A sequence of messages are exchanged with the Teradata Database to establish the Security Context.
8. The encrypted logon message is sent to the Teradata Database.  This message contains the logon source information describing the client process. See LogonSource Format for more information for Teradata DBS versions prior to 14.0 and ClientAttributes for Teradata DBS versions 14.0 and greater. Client Attributes is an extension to logon source information.
9. If the session has an expired password, and NewPassword has been specified, a command is sent to modify the user password. The session is closed, and the process begins again at step 2.
10. A HELP SESSION command is executed to determine information about the Teradata session.
11. If QueryBand has been supplied, a command is sent to the Teradata Database to set the QueryBands.
12. If DataBase has been supplied, a command is sent to the Teradata Database to change the default Database.
13. The TdConnectionStringBuilder.Recovery setting will determine the Recoverable Network Protocol (RNP) and Redrive settings for the application. The default behavior is determined from the Teradata Active System Management (TASM) when the Recovery.Default property is not set.

In This Section

Data Source Resolution

Authentication Mechanism Selection

Authentication String Construction

Logon Source Format

Client Attributes

Database, User ID, Password and Account String Character Repertoire