Accessing SAS Files Across Compatible Machine Types in UNIX Environments

Characteristics of Compatible Machine Types

Different computers store numeric binary data in different forms. Hewlett-Packard, Sun, and IBM store bytes in one order. Linux and Compaq Tru64 UNIX (formerly Digital UNIX) store bytes in a different order. SAS files can be transported between compatible machine types using various methods including NFS, FTP, and CD. For two machine types to be compatible, they must have the following characteristics in common:

• same word length. Word lengths can be either 32-bit or 64-bit.

• same ordering of bytes in memory. Machine types differ in whether the most significant byte (MSB) or the least significant byte (LSB) is loaded at the lower memory address. This is often referred to as "big endian" or "little endian."

Compatible Machine Types for Release 6.12 Through Release 8.2

The tables in this section show the compatible machine types for Releases 6.12 through 8.2. After each table, a brief explanation is provided.

Table 4.3: Compatible Machine Types for Sharing Release 6.12 SAS Files

Bits	Compatible Machine Types
32	Intel ABI, Linux
32	HP-UX, Solaris, AIX, IRIX
64	Tru64 UNIX

You can move a Release 6.12 SAS data set that was created on a 32-bit HP-UX host to a 32-bit AIX host using NFS, FTP, or CD. Because HP-UX and AIX are compatible machine types, you can use the V6 or V6TAPE engine to read the HP-UX data set on the AIX host.

The same 32-bit HP-UX data set can be moved to a 32-bit Intel ABI host. However because these machine types are incompatible, you cannot use the V6 or V6TAPE engine to read the HP-UX data set.

For information about reading Version 6 data sets, see "Reading Version 6 Data Sets" on page 111.

Table 4.4: Compatible Machine Types for Sharing Version 8 SAS Data Sets

Bits	Compatible Machine Types
32	Intel ABI, Linux
32	HP-UX, Solaris, AIX, IRIX
64	AIX, Solaris, HP-UX PA Risc
64	Tru64 UNIX

You can move a Version 8 data set that was created on a 32-bit Solaris host to a 32-bit HP-UX host using methods such as NFS, FTP, or CD. Because these are compatible machine types, you will be able to read this data set in SAS.

The same 32-bit Solaris data set can be moved to a 64-bit HP-UX host. Because these machine types are incompatible, SAS will use CEDA to read this data set. For more information, see "Using CEDA to Read Data Sets" on page 111.

Determining Compatible Machine Types in SAS 9.1

In SAS 9.1, the Data Representation field of the PROC CONTENTS output shows the compatible machine types for a SAS file. The following is a portion of the PROC CONTENTS output.

Output 4.1: Portion of PROC CONTENTS Output Using the V9 Engine

 The CONTENTS Procedure Data Set Name        CLASSES.MAJORS                           Observations          5 Member Type          DATA                                     Variables             6 Engine               V9                                       Indexes               0 Created              Monday, February 24, 2003 14:30:19       Observation Length    48 Last Modified        Monday, February 24, 2003 14:30:19       Deleted Observations  0 Protection                                                    Compressed            NO Data Set Type                                                 Sorted                NO Label               Second Data Set Data Representation HP_UX_64, RS_6000_AIX_64, SOLARIS_64, HP_IA64 Encoding            latin1  Western (ISO) 

 

In this example, the Data Representation field output shows that the compatible machine types for this data set are: HP-UX ( HP_UX_64 ) AIX 64-bit ( RS_6000_AIX_64 ), Solaris 64-bit ( Solaris_64 ) and HP-UX Itanium ( HP_IA64 ). Therefore, you can move a data set that was created on a 64-bit HP-UX host to a 64-bit AIX, Solaris, or HP-UX Itanium host using NFS, FTP, or CD. You could not move this data set to a 32-bit Linux host using these methods. However, you can read this data set using CEDA. For more information, see "Using CEDA to Read Data Sets" on page 111.

The following table lists the possible values for the Data Representation field for SAS 9.1 and the corresponding machine types.

Table 4.5: Data Representation Value for Each Machine Type in SAS 9.1

Data Representation Value	Corresponding Machine Type
ALPHA_TRU64	Compaq Tru64
HP_UX_64	HP-UX PA-Risc 64-bit
HP_IA64	HP-UX Itanium Processor Family
INTEL_ABI	Intel ABI Compliant Operating Systems
LINUX	Linux on Intel 32-bit Hardware
RS_6000_AIX_64	AIX 64-bit
SOLARIS_64	Solaris 64-bit

Note  

The Encoding value might affect your ability to move SAS files between compatible machine types. It is important to note this value when you are transporting SAS files between hosts . For more information about encoding, see SAS National Language Support (NLS): User's Guide .