Moving and Accessing SAS Files across Operating Environments

Traditional Methods for Creating and Restoring Files in Transport Format

Creating and Restoring a Transport File depicts how traditional methods move files between hosts:

Creating and Restoring a Transport File

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This figure shows the creation of a transport file as a means to reconcile incompatible host file formats. The transport file is transferred across the network and the target host restores the file to its native format.

Note: In addition to transferring a transport file over the network, you can also transfer a file to a magnetic medium that can be physically mounted on the target host. [cautionend]

You can use the following SAS statements and procedures to create and restore a transport file, as appropriate.

XPORT engine with DATA step or PROC COPY: At the source host, the LIBNAME statement with the XPORT engine and either the DATA step or PROC COPY creates a data file in transport format. At the target host, the same method is used to translate the transport file into the target host native format.
CPORT and CIMPORT procedures: At the source host, PROC CPORT writes data sets or catalogs or both data sets and catalogs to transport format. At the target host, PROC CIMPORT translates the transport file into the target host native format.

Supported SAS Member Types and Traditional Transport Methods summarizes the methods, according to member type, that can be used to create transport files.

Supported SAS Member Types and Traditional Transport Methods
SAS Member Type XPORT Engine with either DATA step or PROC COPY PROC CPORT and PROC CIMPORT

Data set [bull] [bull]

Catalog
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Benefits of Using the XPORT Engine with PROC COPY

The benefit of using the XPORT engine (with either the DATA step or the COPY procedure) is the ability to move files between hosts, regardless of whether you are moving the transport file to a later or an earlier SAS release.

Note: Regressing a data set (moving from a later release to an earlier release) destroys the features that are specific to the later release. For example, when moving from Version 8 to Version 6, Version 8 long variable names are truncated to eight bytes. For details about file regression, see Regressing SAS Data Sets from Version 8 to Version 6 Format. [cautionend]
Using the XPORT engine is preferable when sending a transport file to a destination host whose SAS release is unknown.

Another advantage of using the XPORT engine is that you can create the transport file once and direct it to multiple target hosts that run different releases.

The primary reason for using the XPORT engine with the DATA step is to dynamically create one or more data sets, to order them, and then to translate them to transport format. By contrast, PROC COPY allows you to translate multiple data sets that already exist in a library.

Limitations of Using the XPORT Engine with PROC COPY

The limitation of the XPORT engine is that it supports only members of type DATA. It does not support members of type CATALOG.

Furthermore, the XPORT engine supports a Version 5-compatible feature set. For example, the XPORT engine cannot support Version 8 features such as long variable names. Warning or error messages report limitations that are encountered during the transport operation. For information about typical error messages and recovery actions for this problem, see File library.member.DATA has too long a member name for the XPORT engine.

The XPORT engine with PROC COPY does not support the transport of any type of view, MDDBs, or DMDBs.

Benefit of Using PROC CPORT and PROC CIMPORT

The CPORT and CIMPORT procedures are preferable for moving members of both type DATA and CATALOG.

Limitations of Using PROC CPORT and PROC CIMPORT

The disadvantage of using PROC CPORT and PROC CIMPORT is that they do not allow the file transport operation from a later version to an earlier version, which is known as regressing (for example, from Version 8 to Version 6). PROC CPORT and PROC CIMPORT move files only from an earlier version to a later version (for example, from Version 6 to Version 8) or between the same versions (for example, from one Version 8 host to another Version 8 host).

However, you can move files between releases of Version 6; for example, from Release 6.12 to Release 6.08. For details about using PROC CPORT and PROC CIMPORT to move files between Version 6 releases, see the Version 6 SAS Language Reference.

PROC CPORT and PROC CIMPORT do not support the transport of any type of view, MDDBs, or DMDBs.

Alternatives to Traditional Methods

None of the traditional transport methods supports any type of view (such as the PROC SQL view), MDDBs, or DMDBs. However, SAS/CONNECT does support these additional member types. For details about SAS/CONNECT, see Using SAS/CONNECT to Transport Files between Hosts.

For file access only, besides supporting members of type DATA and CATALOG, SAS/SHARE also supports PROC SQL views and MDDBs. For details about SAS/SHARE, see Using SAS/SHARE to Access Remote Files.

For file access only, besides supporting members of type DATA and CATALOG, CEDA also supports MDDBs for read-only access. For details about CEDA, see Using Version 8 Cross-Environment Data Access (CEDA).

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