Data Source with Fully Qualified Domain Name can speed up logons plagued with slow "Name to IP-Address resolution".
Applications / users must specify a Data Source (a.k.a. TDPID, DbcName, Server or System Name) in order to connect to Teradata Database. For example SQL Assistant 13.0 prompts for Connection Information:
In this example the Server field is set to TDPID; however a better choice for Server name is TDPID.myCorp.com. In other words we recommend appending Domain Name to the Server Name (Note: Server Name in SQL Assistant corresponds to TdConnectionStringBuilder.DataSource property in .NET Data Provider for Teradata).
A Teradata Database system can have more than one Communication Processor (COP). All COPs are assigned an IP-Address and registered in DNS with a sequential numbering convention; for example sysNameCOP1, sysNameCOP2, … and sysNameCOPn. .NET Data Provider for Teradata will discover/detect all Communication Processors (or Gateways) during the first logon. Data Provider relies on the COP naming/numbering convention; it starts by appending COP1 to the name (e.g. sysName) followed by COP2, COP3, … and COPn until a Host Not Found exception is thrown. Teradata has used the "Cop Discovery" process for years and it usually performs very well. The COP Discovery overall performance is dependent on the performance of Name to IP-Address resolution.
The process of resolving a Name to an IP Address on Microsoft Windows platform is described in Host Name Resolution article. Host Name resolution might result in three separate lookups:
Local Host file lookup
Domain Name System lookup
NetBIOS Name Server (WINS) lookup
NetBIOS Name Server lookup can impact the COP Discovery performance. IPCONFIG command displays whether "NetBIOS over Tcpip" is enabled and whether Name to IP resolution process will continue to WINS servers when there is no entry in Local Host or DNS.
NetBIOS overhead can be avoided by simply appending Domain Name to the Server name. For example specify TDPID.myCorp.com instead of TDPID. So in summary I recommend Fully Qualified Domain Name (FQDN) on Windows platform as a general guideline.