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Using the V7TAPE Engine

In contrast to the V7 engine, the V7TAPE engine does not support indexing and compression of observations. Also, you cannot have a mixed mode, sequential-format SAS data library; you can store only Version 7 or Version 6 sequential SAS data sets on one tape, not some of each.

Note:    For information about accessing SAS files on tape, see Accessing SAS Files on Tape.  

When to Use the V7TAPE Engine

Use the V7TAPE engine to create Version 7 sequential-format SAS data libraries either on disk or on tape and to access files in Version 7 sequential data libraries. The primary purpose of this engine is to enable you to back up Version 7 SAS data sets, catalogs, or whole data libraries. The V7TAPE engine makes it possible to back up applications that contain both SAS data sets and SAS catalogs.

In contrast to the V7 engine, the V7TAPE engine has the following limitations:

• Because the V7TAPE engine is a sequential engine, it cannot be used with the POINT= option of the SET statement or with the FSBROWSE, FSEDIT, or FSVIEW procedure. If you want to use these features of the SAS language with sequential SAS data sets, then use the COPY procedure to copy them to a disk-format SAS data library. (See Notes on Tape Usage.)

• In a single DATA step or PROC step, you can use only one SAS data set from a particular sequential SAS data library.

How to Select the V7TAPE Engine

There are three ways to select the V7TAPE engine:

• Specify V7TAPE as the value of the engine argument in the LIBNAME statement or LIBNAME function, or specify V7TAPE in the Engine: field of the New Library dialog box. You can open the New Library dialog box by issuing the LIBASSIGN command in the command window.

  Note:    Use TAPE as the engine name if you write programs that create new SAS data libraries and you want to create the data libraries in the latest available format. In Version 7, TAPE is an alias for the V7TAPE engine, and it will be an alias for newer sequential engines in subsequent releases.  

• For an existing SAS data library that contains only Version 7 sequential-format SAS data sets, do not specify a value for engine in the LIBNAME statement or LIBNAME function, or select Default as the type in the Engine: field of the New Library dialog box. The SAS System then selects the V7TAPE engine automatically. SAS also selects the V7TAPE engine automatically if you use the DCL DEFINE command to assign an OpenVMS logical name to an existing Version 7 sequential-format data library and then use that logical name as a libref in a SAS file specification.

• Set the value of the SEQENGINE= system option to V7TAPE. This option tells SAS which sequential engine to use as the default when no engine is specified and there are no existing SAS data sets.

Member Types Supported

The V7TAPE engine supports files with all Version 7 member types:

ACCESS	ITEMSTOR
AUDIT	MDDB
BACKUP	PROGRAM
CATALOG	PUTILITY
DATA	SASODS
DMDB	UTILITY
FDB	VIEW
INDEX

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