15.00 - Appendix C ANSI/ISO SQL Compliance - Teradata Database

Teradata Database SQL Fundamentals

prodname
Teradata Database
vrm_release
15.00
category
Programming Reference
featnum
B035-1141-015K

Teradata, like most vendors of relational database management systems, had its own dialect of the SQL language for many years prior to the development of the ANSI/ISO SQL standard. Conformance to a standard presents problems for any vendor that produces an evolved product and supports a large user base.

Teradata, in its historical development, has produced any number of innovative SQL language elements that do not conform to the ANSI/ISO SQL standard, which did not exist when those features were conceived. The existing Teradata user base had invested substantial time, effort, and capital into developing applications using that Teradata SQL dialect.

At the same time, new customers demand that vendors conform to open standards.

Teradata follows these principles for new feature compliance to the ANSI/ISO SQL standard.

 

WHEN ...

THEN ...

a new feature or feature enhancement is added to Teradata SQL

that feature conforms to the ANSI/ISO SQL standard.

the difference between the Teradata SQL dialect and the ANSI/ISO SQL standard for a language feature is slight

the ANSI/ISO SQL is added to Teradata Database feature as an option.

the difference between the Teradata SQL dialect and the ANSI/ISO SQL standard for a language feature is significant

both syntaxes are offered and the user has the choice of operating in either Teradata or ANSI mode or of turning off SQL Flagger. The mode can be defined:

  • Persistently
  • Use the SessionMode field of the DBS Control Record to define session mode characteristics.

  • For a session
  • Use the BTEQ .SET SESSION TRANSACTION command to control transaction semantics.

    Use the BTEQ .SET SESSION SQLFLAG command to control use of the SQL Flagger.

    Use the SQL statement SET SESSION DATEFORM to control how data typed as DATE is handled.

    a new feature or feature enhancement is added to Teradata SQL and that feature is not defined by the ANSI/ISO SQL standard

    If other vendors offer a similar feature or feature extension, Teradata designs the new feature to broadly comply with other solutions, but consolidates the best ideas and, where necessary, creates its own, cleaner solution.

    If other vendors do not offer a similar feature or feature extension, Teradata designs the new feature:

  • As cleanly and generically as possible with an eye toward creating a language element that will not be subject to major revisions to comply with future updates to the ANSI/ISO SQL standard.
  • In a way that offers the most power to users without violating any of the basic tenets of the ANSI/ISO SQL standard.