Innovation Data Processing's Innovation Access Method (IAM) is a high-performance, indexed access method for OS/390 and MVS/ESA operating systems, which offers advantages over the IBM?-provided Virtual Storage Access Method (VSAM). Existing as non-VSAM data sets provides IAM with capabilities to eliminate the 4.3-gigabyte file-size restriction in VSAM prior to DFSMS V1.3, and to choose a block size that optimizes space utilization on DASD.
This article touches on the strengths and weaknesses of both products. It should be noted that BMC Software's RECOVERY UTILITY (RU? ) for VSAM supports both IAM and VSAM files.
What is IAM?
IAM, as noted previously, offers numerous advantages over the IBM-provided VSAM access method. IAM files exist on DASD as non-VSAM data sets, with IAM providing a VSAM-compatible Application Programming Interface (API) for key-sequenced data sets (KSDS) and entry-sequenced data sets (ESDS) file types and any associated alternate indexes.
Existing as non-VSAM data sets provides IAM with capabilities to eliminate the 4.3-gigabyte file-size restriction in VSAM prior to DFSMS V1.3, and to choose a block size that optimizes space utilization on each of the different type of DASD devices and architectures available. Along with IAM's unique file structure and IAM's Data Compression feature, user data stored in an IAM file typically requires substantially less DASD space than when stored in a VSAM cluster.
The maximum size of an IAM file is determined by a set of limitations imposed by DFSMS, MVS and the architecture of the DASD devices. IAM's file-size limitation, based on the IBM 3390 DASD architecture, is approximately 201 gigabytes of compressed user data.
IAM has been in the MVS marketplace for more than 20 years, providing an outstanding level of performance compared to VSAM. IAM offers CPU time savings, along with reductions in EXCPs that result in reduced elapsed times for batch jobs and improved response times for online systems. In the past few years, the most important features of IAM, for many customers, have been IAM's ability to support VSAM data sets that have exceeded 4.3 gigabytes in size and the DASD space savings of IAM's data compression.
Source :
http://ibmmainframes.com/about5359.html
you have to hack into the mainframe
Transfer file from and to mainframe using FTP You can use FTP dos command to transfer files from and to mainframe Step1: Start --> Run --> Command Step2: Enter the following command FTP XX.XXX.XX.XXX Where XX.XXX.XX.XXX is the ip address of mainframe Step3: When you are prompted for user name and password, provide your mainframe id and mainframe password Step4: To download the file from mainframe to PC Get 'FIIE.ON.MAINFRAME' D:\MYFILES\TEST.TXT To Upload the file to mainframe from PC PUT D:\MYFILES\TEST.TXT 'FILE.ON.MAINFRAM'
File Transfer Protocol was originally used for the exchanging data between incompatible mainframe systems. Then, it was used by people using the Internet as a way to exchange files between personal computers.
short history of mainframe
The IBM zEnterprise 196 mainframe
what is memorey capacity of the mainframe computers
Mainframe - comics - was created in 1999.
Yes, Linux can be used on a mainframe.
Insane in the Mainframe was created on 2001-04-08.
Douglas Engelbart did not invent the mainframe computer.
Computers, Which are technically superior to mainframe are called super computers.
Mainframe is basically use for bulk data processing and critical data.