Dictionaries and Runtime Environments › Runtime Environments

Runtime Environments

Central Version or Local Mode

CA IDMS/DB can run within a DC/UCF system as a central version or in local mode:

• Central version operations provide database services to batch or online applications. Multiple users can gain access to a database concurrently.
• Local mode operations are batch operations that do not run under a central version. In local mode, only one user at a time has access to a database area in update mode.

Data Sharing Environment

Data sharing is an environment in which two or more central versions operate cooperatively through the use of a coupling facility. In this environment, multiple central versions may concurrently access a database area in update mode.

Central Version Runtime Components

The following table lists the components needed for a central version runtime environment:

Considerations

• The segment name of the system message area must be SYSMSG.
• The segment(s) associated with DDLDCLOG and DDLDCRUN must be included in the SYSTEM database name.
• Each central version must have its own DDLDCLOG. In a non-data sharing environment, each central version must also have its own DDLDCRUN area. In a data sharing environment, the DDLDCRUN area may be shared among members of a data sharing group.
• The DDLDCSCR component is not needed if scratch information is maintained in memory. If the DDLDCSCR component is used, each central version must have its own and the segment associated with the DDLDCSCR must be included in the SYSTEM database name.
• The DDLSEC area may not be necessary depending on your security implementation.
• The SYSTRK reference is needed if change tracking is in effect for the central version.

More Information

• For more information about sharing the DDLDCRUN area, see the CA IDMS System Operations Guide.
• For more information about security, see the CA IDMS Security Administration Guide.
• For more information about specifying the location of scratch information, see the CA IDMS System Generation Guide.
• For more information about Change Tracking and referencing SYSTRK files, see "Change Tracking" in the CA IDMS System Operations Guide.

Local Mode Runtime Components

The following table lists the components needed for a local mode runtime environment:

Considerations

The segment name of the system message area must be SYSMSG.

• The DDLSEC area may not be necessary depending on your security implementation.
• The DDLOCSCR is always optional. If it is not available, scratch information is stored in memory or in the DDLDCSCR area.
• At least the default dictionary should be available in local mode. Additional application dictionaries may be needed for loading subschemas and processing SQL requests.
• Including a reference to a SYSTRK file is only available if the central version is using change tracking.

More Information

• For more information about security, see the CA IDMS Security Administration Guide.
• For more information about specifying the location of scratch information, see the CA IDMS System Generation Guide.
• For more information about Change Tracking and referencing SYSTRK files, see "Change Tracking" in the CA IDMS System Operations Guide.