Joined: 02 Dec 2003 Posts: 151 Location: Tokyo, Japan
1) Advantages of Mainframe -
i) Huge memory.
ii) High speed compared to volume of data.
iii) High security;no virus attack so far reported in last 50-60 years.
Mainframe projects are still there because-
i) They are running without any major problem.
ii) Huge cost associated with the conversion of mainframe based system to open system like Java..
iii) There are lots of example in Industry where attempts are made to shift mainframe to some other LATEST technology but has to roll back due to many problem. I can give you example of AIG where I worked. They tried to shift mainframe to a unix based system. They rent HP lab for volume testing and it takes 3 days to complete the batch whereas Maniframe takes only 8.5 hrs. They returned to mainframe without any second thought. I was involved in the project of this rollback.
iv) Security is again a big issue in Banks and other financial organisations.
v) I have seen Oracle crashing with 15 lakhs data which is very common in industry but DB2 works well with this volume.
But in some caes it is changing. I-Flex banking product FLEXCUBE is replacing COSMOS in Citibank which is a mainframe based system.
2) Atleast I can tell you that if you enter into the wotld of mainframe you don't have to think about your job cut. It has a stable market for the last 20 years. Industry has seen the downfall of Java based technology in recent past.
3) I agree that most of the projects are coming from US not only mainframe but still there are lot of branches of these MNCs in other country like Japan, Singapore, Thailand and even in China.
The Indian Railway reservation system is based on mainframe only. Major technical part of TISCO is based on Mainframe.