Using SAS Engines

The V6 Engine under OpenVMS

Starting in SAS System 9, the V6 engine is read-only. You use this engine to read Version 6 libraries. The V6 libraries are disk-format libraries, probably the most common type of libraries. With this engine, you will not be able to write directly to these libraries. For more information about the V6 engine, see SAS Language Reference: Concepts.

Member Types Supported

Because the V6 engine is read-only, it supports only the DATA member type. This engine does not support indexing.

Engine/Host Options for the V6 Engine

The V6 engine provides one engine/host option that controls the access of SAS data sets. This option corresponds to an option that is available through OpenVMS Record Management Services (RMS).

You can use the following engine/host option with the V6 engine:

CACHESIZE=

controls the size (in bytes) of the data cache used to buffer I/O pages. The value can range from 0 to 65,024. By default, the chosen value is an even multiple of the file's page size. A value of 0 specifies to use no data cache. Memory is consumed for the data cache, and multiple caches can be used for each data set opened. The disadvantage of large CACHESIZE= values is large consumption of memory. The advantage of large CACHESIZE= values is a reduction in the number of I/Os required to read from or write to a file.

The CACHESIZE= and BUFSIZE= options are similar, but they have important differences. The BUFSIZE= option specifies the file's page size, which is permanent. It can be set only on file creation. The CACHESIZE= option is the size of the internal memory cache that is used for the duration of the current open, so it can change any time the file is opened. Also, BUFSIZE= cannot be used as an engine/host option; it is valid only as a data set option.

For additional details, see CACHESIZE= Data Set Option: OpenVMS.

Data Set Options Supported by the V6 Engine under OpenVMS

For a list of the data set options that the V6 engine recognizes, see Summary Table of SAS Data Set Options under OpenVMS. The engine/host options discussed in Engine/Host Options for the V6 Engine can also be used as data set options when you use the V6 engine.

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