Pubsets

Standard pubsets cannot contain any large objects. Only LARGE_OBJECTS pubsets are able to accommodate large objects. Two types of these pubsets are available:

• LARGE_OBJECTS pubsets without large files:

  This pubset type allows large volumes, but limits the file size allowed to 32 GB. This means that the pubset may contain volumes >= 32 GB, but necessarily does not currently contain such volumes.

  The introduction of large volumes can only affect the PHP of the extent lists, a value which is of no interest to the application program and cannot under any circumstances be directly altered by it. Thus, this pubset type allows large volumes to be integrated into existing application programs with (almost) no problems. From the point of view of the user, these pubsets behave (almost) as conventional pubsets.

• LARGE_OBJECTS pubsets with large files:

  This pubset type allows large volumes and large files, but they do not necessarily exist.

  It allows large files to be separated from programs that use interfaces that are incompatible and supports the step-by-step introduction of large volumes and - at a second step - of large files.

Both new pubset types are only recognized as of OSD-BC V5.0 and can imported on all BS2000 versions which are currently released.

Large objects are supported by both SF and SM pubsets. To achieve this, two additional attributes exist:

LARGE_OBJECTS	Attribute for supporting volumes >= 32 GB
LARGE_FILES_ALLOWED	Attribute controls whether large files (files >= 32 GB) are also supported

In the case of SM pubsets, the attributes LARGE_OBJECTS and LARGE_FILES_ALLOWED are also properties of the pubset, rather than of (individual) volume sets, since volume sets would otherwise be visible on different interfaces to the user and could cause incompatibilities.

Figure 1: Attributes of LARGE_OBJECTS pubsets

Defining LARGE_OBJECTS pubsets

The properties LARGE_OBJECTS and LARGE_FILES_ALLOWED are static and can be specified when configuring the pubset with SIR (see section "Installing and extending LARGE_OBJECTS pubsets with SIR").

Using the SET-PUBSET-ATTRIBUTES command, existing standard pubsets can be upgraded to LARGE_OBJECTS pubsets with and without support for large files (see section "SET-PUBSET-ATTRIBUTES / SHOW-PUBSET-ATTRIBUTES"). The following upgrades are possible in this context:

Standard pubset --> LARGE_OBJECTS pubset with large files

and

Standard pubset --> LARGE_OBJECTS pubset without large files --> LARGE_OBJECTS pubset with large files

When the pubset is imported, the attributes are added to the MRSCAT.

Warning!

Conversion back to a standard pubset is not possible.

The existence of large files can in certain cases affect the executability of applications (see chapter "Users and programmers").

Summary of pubset management interfaces affected by 32 GB objects

Interface	Change
Privileged commands
SET-PUBSET-ATTRIBUTES	Specification whether existing pubsets are to be upgraded to LARGE_OBJECTS pubsets with or without large files.
SET-PUBSET-ATTRIBUTES	Two S variables display the attributes LARGE-VOLUMES and LARGE-FILES: var(*LIST).LARGE-VOL and var(*LIST).LARGE-FILE
SHOW-MASTER-CATALOG-ENTRY	Output of LARGE_OBJECTS properties for LARGE_OBJECTS pubsets
Macros
STAMCE	Output of MRSCAT entries related to LARGE_OBJECTS
Privileged utilities
SIR	Installing and extending pubsets, initializing volumes in respect of LARGE_OBJECTS