The ESS/400 Access Library is a set of routines which provide record level access and management of data in files residing on a Distributed Data Management (DDM) target such as the IBM AS/400. This library allows the PC programmer to write an application which will be able to open, lock, access, modify, unlock and close files on a DDM target system. Thus the software developer can create a true cooperative processing application.
Cooperative processing is defined as the sharing of the process. In this case it is referring to the process of integrating PC programs with host AS/400 native database information. Distributing the application execution workload among PC workstations reduces the resources needed on the host system and gives the developer the ability to choose tasks suited to a given processor. More efficient and cost-effective applications are developed by sharing the workload among several processors.
Record level access is defined as access to data in a file on an individual record boundary. Instead of downloading the entire file, the ESS/400 linkable library provides access to that same data on an individual record. This gives the programmer the capability of accessing only the record(s) of the file necessary to do the processing in the application.
The ESS/400 Cooperative Processing interface provides sub-second response time to a host record request. Only the requested record is in the PC memory after the request is executed. The PC application performs the desired function on the data and returns the record to the host file. ESS/400 does not interfere with existing host based programs accessing the same record(s) because ESS/400 provides for standard record locking capabilities and does not bypass host security processes. Thus host data security and integrity are ensured.
With ESS/400 it is possible to create a PC application using popular application development tools for Windows. These PC applications will use less host resources, provide for a more appealing user interface, run faster than most host applications and integrate with other advanced PC products.
ESS/400 requires no additional host code for the IBM AS/400 compatible router software. Access to systems other than the AS/400 is not supported in this release of ESS/400.