It
is necessary to describe the organization, of the data in a formal
manner. The logical and physical database descriptions are used by DBMS
software. The complete and overall description of data is referred to as
schema, The schema and subschema words are brought into DBMS by CODASYL
(Conference on data system language1 committee) and also by the
CODASYL’s database task group. Schema is also referred to as conceptual
model or global view (community view) of data. Suppose a complete
description of collected data having all classes and student data4 all
employees (teaching & non-teaching) data and other concept of data
related to the college is called Schema of the college. We can say that
we relate whole college data logically, which is called schema.
Pointers are an extremely powerful programming tool. They can make some things much easier, help improve your program's efficiency, and even allow you to handle unlimited amounts of data. For example, using pointers is one way to have a function modify a variable passed to it. It is also possible to use pointers to dynamically allocate memory, which means that you can write programs that can handle nearly unlimited amounts of data on the fly--you don't need to know, when you write the program, how much memory you need. Wow, that's kind of cool. Actually, it's very cool, as we'll see in some of the next tutorials. For now, let's just get a basic handle on what pointers are and how you use them. What are pointers? Why should you care? Pointers are aptly name: they "point" to locations in memory. Think of a row of safety deposit boxes of various sizes at a local bank. Each safety deposit box will have a number associated with it so that you ca...
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