Reading SAS Files from Previous Releases or from Other Hosts

Reading Version 6 Files

Using the V6 read-only engine, SAS can read Release 6 data sets that were created by compatible computer types. In most cases, SAS invokes the V6 engine automatically, and you do not have to specify it. The following examples demonstrate how you can use the V6 engine.

If you are running SAS 9.3 on Linux, you can use the V6 engine to read Release 6 data sets that were created with any Intel ABI release of SAS, such as SCO UNIX.
If you are running SAS 9.3 on HP-UX, you can use the V6 engine to read Release 6 data sets that were created on HP-UX, Solaris, AIX, or IRIX.

For a list of the compatible computers types for V6, see Compatible Computer Types for Release 6.12 through SAS 9.3. For more information about the compatibility of Version 6 files with SAS 9.3, see SAS Language Reference: Concepts.

Reading Version 8 or Later Files from Compatible Computer Types

If your files were created in 64-bit SAS, they are compatible with SAS 9.3. You do not need to use CEDA to read your files. To view tables that show compatible computer types for Release 6.12 through SAS 9.3, see Compatible Computer Types for Release 6.12 through SAS 9.3.

Reading Version 8 or Later Files from Incompatible Computer Types

Compatibility of Existing SAS Files with SAS 9.3

In Release 8.2, both 32–bit and 64–bit SAS were available for the AIX, HP-UX, and Solaris operating environments. In SAS 9, SAS for these environments is 64-bit only. Some SAS files that were created in 32-bit releases of SAS cannot be read by the V9 engine.

SAS automatically tries to use CEDA to read data sets. If you use CEDA to read a data set, and include msglevel=i in your code, then SAS writes a note to the log.

Release 8.2 files that are 64–bit and that were created on a UNIX computer are native on UNIX for SAS 9. You do not need to migrate these files.

The following table lists the supported processing for each SAS file under CEDA.

Supported Processing for Release 8 32–Bit Files in SAS 9

File Type	Support
SAS files	input processing, output processing (In SAS 9, if you create a new data file from the 32–bit file, the new file is generally 64–bit. For more information about CEDA, see SAS Language Reference: Concepts, or Migration at the Technical Support Web site.
MDDB file	input processing
PROC SQL view	input processing
SAS/ACCESS view for Oracle or Sybase	input processing
SAS/ACCESS view other than for Oracle or Sybase	no support
SAS catalog	no support
stored compiled DATA step program	no support
DATA step view	no support
item store	no support

Note: In SAS 9, if you create a new file from a 32–bit file, the new file is generally 64–bit. For more information about CEDA, see SAS Language Reference: Concepts, or Migration at the Technical Support Web site.

Accessing Version 8 or Later Files with CEDA

CEDA enables a SAS data set that was created in Version 8 or later in any directory-based operating environment (such as UNIX and Windows) to be read by a SAS session that is running in another directory-based environment. In SAS 9.3, if you try to access a data set that was created in a previous release, then SAS automatically uses CEDA to process the file. For example, if you are running SAS 9.3 on Linux, SAS uses CEDA to process a data set that was created in Release 8 on a 64-bit Solaris host. With CEDA, you have Read and Write access to these files. However, you will not be able to update the file. For information about compatibility, see Migration at the Technical Support Web site.

For best system performance, it is better to use data sets that are in the native format. Otherwise, CEDA might require additional CPU resources and might reduce system performance.

If you need to access 32-bit SAS data sets, SAS/ACCESS views from Oracle or Sybase, SQL views, or MDDB files from a 64-bit SAS session, then you can access these files using CEDA. CEDA provides Read and Write access to these files. However, CEDA does not support Update processing. CEDA consumes additional resources each time you read or write to these files.

Catalogs and other SAS files (not including SAS data sets) contain data structures that are known only to the application that created them. These catalogs and files might contain data objects other than character or numeric objects and, therefore, cannot be shared between 64-bit SAS and earlier 32-bit releases of SAS.