|Moving and Accessing SAS Files across Operating Environments|
The data transfer services in SAS/CONNECT also moves data between versions of SAS software as well as across hosts. Many organizations may find it necessary to operate in a mixed-version environment while making a transition from Version 6 to Version 8. This environment includes a mixture of local or remote hosts running either a Version 6 session or a Version 8 session.
Whenever possible, it is generally recommended that you keep Version 6 and Version 8 SAS files in separate physical locations. This will avoid any potential confusion as to which file is being accessed. If mixed versions are stored in the same library, the appropriate engine should be specified when accessing the SAS data files. For more details about operating in a mixed library environment, see Using SAS/SHARE to Access Remote Files.
Version 8 offers several new features that make Version 8 data files incompatible with Version 6 data files. However, for new features that involve increased character length, SAS/CONNECT truncates the character length in an attempt to produce a Version 6 compatible data file. This allows you to take advantage of some of the new Version 8 features while operating in a mixed-version environment. The Version 8 features that SAS/CONNECT is able to truncate are:
Other new Version 8 features cannot be modified to make data files compatible with Version 6. Therefore, any attempt to transfer data files that contain these features will fail. Some of the new features that cannot be modified to be Version 6 compatible include:
Version 8 supports longer names and labels than those supported in Version 6. The longer names and labels are stored in Version 8 data files, which makes them incompatible with Version 6. SAS/CONNECT implements a set of truncation rules to convert a Version 8 data file that contains long names and labels back into a Version 6 data file.
SAS/CONNECT applies the truncation rules during file transfer
Note: In order to produce a Version 6 data file, you set the
SAS option and value VALIDVARNAME=V6 in the session that creates the data
file. With VALIDVARNAME=V6 set, the truncation is performed when running the
V8 engine or the V6 engine.
In either case, the following rules are applied for data sets that have long data set labels, long variable labels, and/or long variable names. In each case, the length is truncated to the length that is supported by Version 6.
Note: If the variable label field is blank, the long
name is copied to the label field.
The truncation algorithm that is used to produce the 8-character variable name also resolves conflicting names.
|Version 6 Local Host Accessing a Version 8 Remote Host|
This section summarizes the limitations of a Version 6 local
host that accesses files on a Version 8 remote host in a cross-version environment.
All data format conversions are performed when transferring
a data file and do not require any user invention. PROC UPLOAD produces a
Version 8 data file when transferring data files from a Version 6 local host.
PROC DOWNLOAD provides full support for the transfer of Version 6 data files
residing on the remote host. However, Version 8 data files can be downloaded
to a Version 6 local host and will follow the truncation rules provided that
the data files do not contain any other Version 8 specific features.
In order to upload or download PROC SQL views, a Version
6 local host can use the DATA= option in the procedure to specify the data
file that is associated with the view to be transferred. Alternatively, the
Version 6 local host can use the INLIB= option in the procedure to specify
the library for transfer.
A Version 6 local host can upload a Version 6 catalog, but the resulting catalog is in Version 8 format. A Version 6 host can download Version 6 or Version 8 catalogs as long as the entry type is backwards compatible.
|Version 8 Local Host Accessing a Version 6 Remote Host|
This section summarizes the limitations of a Version 8 local
host that accesses files on a Version 6 remote host in a cross-version environment.
A Version 8 data set can be uploaded to a Version 6
remote host and will follow the truncation rules describe earlier, provided
that the data sets do not contain any other Version 8 specific features. PROC
DOWNLOAD transfers Version 6 data sets to the Version 8 local host.
A Version 8 local host can upload data that is associated
with a view to a Version 6 remote host and will follow the truncation rules.
A Version 8 local host can download a Version 6 catalog from a Version 6 remote host. A Version 6 catalog can also be uploaded from the Version 8 local host if the entry type is backward compatible.
Note: The Version 8 local host cannot use PROC UPLOAD
to create a Version 6 catalog entry because Version 6 catalogs are read-only
in Version 8.
Version 8 cannot read Version 6
catalogs on an AIX UNIX host.
In order to move Version 6 catalogs to Version 8 format on AIX hosts, you
must use PROC CPORT and PROC CIMPORT.
SAS/CONNECT supports moving some catalog entries between Version 8 and Version 6. Version 8 entry types that are backward compatible with Version 6 are:
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