SAS Companion for the OpenVMS Operating Environment

Sharing Data between OpenVMS Platforms

SAS files that were created in an OpenVMS operating environment other than the one on which the user is currently running are described as nonnative. For example, data sets that were created on the VAX platform are defined as nonnative when they are moved to an Alpha platform.

Nonnative data must be converted before it can be accessed. There are two ways to convert nonnative data:

convert the data "transparently" between the OpenVMS VAX format and the OpenVMS Alpha format each time you access the file. This method causes performance degradation.
convert the data to the local format one time only. This method is more efficient, eliminating the need to convert the data each time you access it.

The following is an example of how you can convert a file:

data a;
   set b;
run;

This code reads file B, which is in nonnative format, and creates a native version A.

A limitation of the one-time-only conversion is that the OpenVMS VAX platform supports a minimum numeric variable length of 2 bytes. The OpenVMS Alpha platform supports a minimum numeric variable length of 3 bytes. Therefore, using this method to move data from the VAX platform, which supports 2-byte numeric storage, to the Alpha platform, which supports 3-byte numeric storage, is not permitted. Instead, to move data from the VAX platform to an Alpha platform, you must use the VAXTOAXP procedure. Consequently, there is a potential loss of numeric precision when you move data from a VAX platform to an Alpha platform. For more information, see Data Representation. For more information about the VAXTOAXP procedure, see VAXTOAXP.

Note: In Version 8, the VAXTOAXP procedure increases VAX numeric variables of length two to seven characters by one character to minimize loss of precision. [cautionend]

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