M-Pact Data Compression System
M-Pact combines two powerful BIMoyle tools, BIMCMPRS and PACK, to create a complete disk storage and compression package.
BIMCMPRS is a program product used to compress 3270 CRT or printer output data streams. This reduces response time and reduces contention among terminals on the same network.
BIMCMPRS functions by removing repetitive characters from the data stream and rebuilding the screen (or printer) buffer so that the 3270 will construct the intended image at the terminal. An optional feature, called "inbound compression," may be used to further reduce transmission by suppressing characters known to already be on a CRT screen. Transmission reduction typically varies between 15 and 75 percent, depending on application programs and data entered by terminal operators. Response time improvement depends on the reduction amount and the network speed.
BIMCMPRS is supplied with a CRT transaction which is used to display statistics on the compression effectiveness. The transaction displays terminal I/O counts, character totals before and after compression, and calculates compression percentage, for all local terminals collectively, all remote terminals, and for each individual terminal. BIMCMPRS supports all telecommunication protocols (BTAM, TCAM, VTAM) under VSE.
BIM-PACK addresses one of the major problems of today's computer installations, disk storage. With the ever increasing demands to keep more and more data on-line, computer installations are faced with the need to continually install more disk storage devices with even greater storage density and capacity. This situation leads to the inevitable problems of the cost of more disk drives, floor space for the new disk drives and controllers, air-conditioning upgrades, and the scheduling of long running backup jobs with their ever increasing number of magnetic tape reels. If you use VSAM and are not using BIM-PACK you are probably wasting valuable disk space. Many installations have files that contain records where a only a small amount of the record is used, giving rise to large areas of unused space, and records not being efficiently blocked into VSAM Control Intervals and accordingly Control Areas.
BIM-PACK addresses these problems for Entry- and Key-Sequenced VSAM files by allowing the user to compress the data on selected files, and thus reduce the amount of space required to hold such files.
The amount which can be saved by compression depends on the contents and layout of the user's records, and the degree of compression chosen by the user. Compression of more than 70% has been achieved by BIM-PACK's sophisticated algorithms.
BIM-PACK includes a file analysis program which can be run against selected files to establish the potential compression ratio, and thus the value, of using BIM-PACK for the file and the site generally.
BIM-PACK is fully transparent to programmers, operators, and application programs. Selected files are re-DEFINED and reloaded, after which the compression process is automatic and invisible.
EXTEND/DASD VSAM Compression for VSE