Accessing Simultaneous Usage Data Sources

In this section:

How to:

The FOCUS Database Server is a batch job or started task managing all READ/WRITE operations to a FOCUS data source.

Syntax: How to Access Simultaneous Usage Data Sources 

USE 
fileid ON server 
END

where:

fileid

Is the ddname of the FOCUS data source allocated in the batch job or started task.

Example: Accessing an SU Data Source

To use the EMPLOYEE FOCUS data source allocated to the FOCUS Database Server batch job or started task, two things must be done:

  1. Allocate a ddname to the communications data set that is allocated in the FOCUS Database Server batch job or started task pointed to by the ddname FOCSU.

    For example, 

    DYNAM ALLOC FILE MYSERVER DS prefix.FOCSU.DATA SHR
  2. Issue the USE command for your data source allocated in the batch job or started task. For example:
    USE
EMPLOYEE ON MYSERVER
END

Multi-Thread Configuration

How to:

Performance gains may be achieved by routing read-only requests directly to the data source on disk instead of through the FOCUS Database Server. This is called a multi-thread configuration. It is accomplished with the USE command and the keyword LOCAL.

Syntax: How to Read SU Data Sources in a Multi-Thread Configuration

Allocate the FOCUS data source and issue the USE LOCAL syntax: 

DYNAM ALLOC FILE EMPLOYEE DS prefix.EMPLOYEE.FOCUS SHR
DYNAM ALLOC FILE MYSERVER DS prefix.FOCSU.DATA SHR
USE
EMPLOYEE ON MYSERVER
EMPLOYEE LOCAL
END

For more information about Simultaneous Usage Mode, see your Simultaneous Usage documentation.

Note:

  • On a FOCUS Database Server, 255 data sources can be open at one time with 512 users connected.
  • The READ option is available for accessing an SU data source with an alternate Master File (using an AS name). For example:
    USE EMP01 AS EMPLOYEE ON MULTID READ

    In an SU environment, the READ option does not provide read-only access. It is required because alternate Master Files are not supported in SU for MODIFY and MAINTAIN.