single tier example
"In a mainframe based applications , all the enterprise presentation logic , business logic , data access logic and data are interwined in single node.....this is single tier"
is it true ? mainframe is like that !! everything in one place !
i dont know how mainframes are written ...i guess ...this is in one file ...does mainframe really have one and only one file in its application :-)
this is not java related question probabily ...if anybody have idea on mainfraME please post your knowledge
thank you
You can write multi-tier applications on the mainframe just like any other environment, but often much or all of the logic is intermingled within one set of programs and not specifically separated.
Some languages are more suited to this approach than others because they were designed that way (e.g. the so-called 4GLs such as Natural, Ideal, ObjectStar, etc).
Additionally, a lot of mainframe programs are "batch" programs - they run standalone with no user interface. In these programs, performance is almost always the driving force behind the way they are designed and therefore how much or how little the Business logic is separated from the database access etc.
One and only file? I don't see them mentioning a single file anywhere.
And mainframes aren't written, they are big physical boxes (well, computers) that were popular back in the days. Instead of having, let's say a database server and a webserver in different boxes connected by network, a mainframe would be a self-contained workhorse that does everything.
You could buy a mainframe from here for example http://www-03.ibm.com/systems/z/
I wouldn't talk about them in the past tense - they are still very much in current use. My company (a Bank) uses several and all our major systems run on them, even if the front-end may now often be a client-server arrangment on Unix or Windows.
that depends on your definition of "big" of course.
With people ever more used to miniaturised devices like GSM phones and PDAs they think a regular desktop PC is "big".
Those people would consider today's mainframes and minis to be massively huge, can't even conceive the idea of a 1970s mainframe that would take up a small (or not so small) building.
