Protected Mode Process/Server Administration for External Routines | Vantage - Protected Mode Process and Server Administration for C/C++ External Routines - Analytics Database - Teradata Vantage

SQL External Routine Programming

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-07-11
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iiv1628111441820.ditamap
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dita:id
B035-1147
lifecycle
latest
Product Category
Teradata Vantageā„¢

Executing C or C++ external routines in protected mode requires additional administration.

The database installation process creates a local, operating system-native user with the name 'tdatuser' on each node the database runs on. The 'tdatuser' ID is associated with two default processes per AMP vproc and PE vproc for running external routines in protected mode.

Follow these rules to guarantee that your external routines and database function properly:
  • Do not delete 'tdatuser'.
  • Do not add a password for 'tdatuser'.

    This prevents logon to the user on the system.

  • If you think you need to make changes, please contact the Teradata Support Center first.

In addition to creating 'tdatuser', the installation process also creates a new group on each node called 'tdatudf'. The preceding admonishments apply to the 'tdatudf' group: do not change it.

The 'tdatuser' user has no special privileges on the system. No one should be able to log on as 'tdatuser'.

If an external routine that runs in protected mode needs to access system resources, to open a file for example, you must set the appropriate access privileges to include 'tdatuser'.

By default, each vproc has only two protected mode servers that are shared among all transactions executing protected mode external routines. To increase the number of protected mode servers per vproc, use the cufconfig utility. For more information, see Teradata Vantageā„¢ - Database Utilities, B035-1102.

A table function that executes in protected mode reserves a server process for the duration of the step that executes the table function. It is important that the number of protected mode servers that you allocate is greater than the number of simultaneous queries from different sessions that you plan to run. If you allocate too few, then some will have to wait. If all the servers are used up, an undetected deadlock could also occur.