17.10 - Considerations - Access Module

Teradata® Tools and Utilities Access Module Programmer Guide

Product
Access Module
Release Number
17.10
Release Date
June 2021
Content Type
Programming Reference
Publication ID
B035-2424-061K
Language
English (United States)
When writing an Access Module, the following rules apply:
  • All functions are invoked with support of two parameters:
    • General function-independent specifications
    • Function-dependent specifications
  • Use an initialization function first, before any other.
  • Specify all buffer and record lengths as multiples of the sizeof(pmChar_t) value.
  • Free all buffer areas that are created by an Access Module when they are no longer needed.
  • The passing of error text to the Data Connector API (for display by the client) is supported by a buffer allocated by the Access Module. The Access Module can assume the buffer is no longer required on the next entry to the Access Module; that is, the buffer is freed the next time the Access Module is called.

UNIX signals are predefined messages sent between two UNIX processes to communicate the occurrence of unexpected external events or exceptions. If UNIX signals are incorporated into an Access Module or routine, an error results.

For a list of UNIX signals used by a particular Teradata utility, see the corresponding Teradata documentation. For example, one of the signals used by Teradata FastLoad is SIGUSR1, which is documented in Teradata® FastLoad Reference, B035-2411.