SHAREOPTIONS

Syntax

SHAREOPTIONS(crossregion [crosssystem])

Options

crossregion specifies the sharing allowed among regions within the same system or within multiple systems using a single lock manager. Independent job steps in a JES region, or multiple JES regions using a single lock manager, and/or multiple CICS users, can have concurrent access. The user must use DISP=SHR in the data set's DD statement to share the data set. You can use these options:

• 0 - SHAREOPTIONS values are not applied to the DSN.
• 1 - The data set can be shared by multiple users for read-only processing, or by a single user for read and write processing.
• 2 - The data set can be accessed by multiple users for read-only processing, and can also be accessed by a single user for write processing.
• 3 - The data set can be fully shared by multiple users. Each user is responsible for maintaining both read and write integrity of the program data.
• 4 - The data set can be fully shared by multiple users. Each user is responsible for maintaining both read and write integrity of the program data. VSAM refreshes the buffers used for direct processing before each request.

crosssystem defines the sharing allowed among systems. Cross-system sharing is not yet supported. However, any value set for crosssystem is read and stored in the catalog and in the data file, which can be included when sending a job step to the mainframe for processing. The values are:

• 0 - SHAREOPTIONS values are not applied to the DSN.
• 1 - Reserved.
• 2 - Reserved.
• 3 - The data set can be fully shared by multiple users. Each user is responsible for maintaining both read and write integrity of the program data.
• 4 - The data set can be fully shared by multiple users. Each user is responsible for maintaining both read and write integrity of the program data. VSAM refreshes the buffers used for direct processing before each request.

Description

The cross-region parameter applies to either a single region or all regions that are part of an ES Cluster.

VSAM SHAREOPTIONS may be specified for a data set using the IDCAMS DEFINE CLUSTER command, together with the associated DATA, INDEX and AIX components, or the ALTER command. Unlike the mainframe, there is no default value. If the option is not specified then the additional share option processing is not performed. This is to ensure backward compatibility with existing file processing, and is equivalent to specifying SHAREOPTIONS option values of 3,3. If a data set with SHAREOPTIONS is being used by CICS, the FCT must be set to use the cataloged data set. Using the share options does involve additional processing so unless it is required, it is best not to set values for the options.

To nullify an existing SHAREOPTIONS setting, so that it is not used, you can use the ALTER command to set the value to (0,0).

Restrictions

Because a single lock manager is used, options are only valid within a single region or within multiple regions that are part of an Enterprise Server cluster.

Since the parameter values are held in the catalog record, all regions that wish to use VSAM SHAREOPTIONS must also be JES enabled. The crossregion option applies to either a single region or all regions that are part of an ES Cluster. The crosssystem option is not processed as both option 3 and 4 are the equivalent of the current file handling process. Within the Micro Focus File Handling system there is no difference between options 3 and 4 for either crossregion or crosssystem.

The crossregion options values 3 and 4 are considered the same because the File Handler has knowledge of the file state and refreshes data as required.

VSAM SHAREOPTIONS must not be modified for a file while the file is open.

Because there is no default value it is important to specifically set a SHAREOPTIONS value if you wish it to be used. All the CLUSTER and AIX components should have the same SHAREOPTIONS value, so that any of the components can be referenced by a batch job or by a CICS FCT and participate in the controlled shared access using the same value.