What are the drawbacks of current commercial databases?

Answer 1

With a DBMS, you lose the intrinsic control of data management that exists in an integrated software solution. For instance, if you were to write a program in C++, you have the option to directly control how your program's data is handled by the actual memory on the host computer, how that memory is addressed and allocated and cached stored on the disk, even on a bit by bit level if you so choose.

On the programming layer, you also have direct control over how

different tasks will operate on your data as well. So instead of creating related tables in a relational system and using SQL to manipulate that data you can create routines that will directly manipulate the data to your exact specifications.

So, instead of building tables you may store you data in a linked list or binary tree, which if you're good, could show very, very significant improvements for tasks such as searching and sorting. A DBMS does mostly the same task, however they've devised a very general way of organizing data that works generally for all problems. If you build a custom data solution instead of taking direct routes you can find ways to optimize your code in a way that cuts through the structure and performs tasks just not possible on a DBMS.

However, considering the amount of work that goes into creating an integrated data solution and the strong likelihood that information theory experts/gods who actually work for database companies like Oracle are way, way better programmers then you, there is probably no significant advantage to not using a DBMS unless the ammount of data you are handleing is very small.

PS: I recommend postgresql. People will try to tell you how great mysql is, but its because they're weak. PGSQL is the best DB you can get for nothing in the world. Good luck.

Answer 2

The network database model implements application logic in the data structure that limits the flexibility. In the network model, there is always the "first" in the table, and the "last" in the table. If you read the table, you always read it the same way. The database allows you to implement "joins" as sets - and they are always ready. The "union" can be empty, it can have a first and last member and members can refer to other tables. If the systems requires a number on the invoice, you cannot store the invoice without giving it a number.

But then, if the application logic changes you need to restructure the database and add indexes that the users can use to improve the new logic. If you add a field, you have to restructure the entire table (or "realm").

It is fast when used as intended, it is easy to write applications for, but is not intended for new use.

Answer 3

Database systems are complex, difficult, and time-consuming to design

Substantial hardware and software start-up costs

Damage to database affects virtually all applications programs

Extensive conversion costs in moving form a file-based system to a database system

Initial training required for all programmers and users

Answer 4

Existing commercial DBMS, both small and large has proven inadequate for these applications. The traditional database notion of storing data in two-dimensional tables, or in flat files, breaks down quickly in the face of complex data structures and data types used in today's applications. Research in model and process complex data has gone in two directions:

a. Extending the functionality of RDBMS

b. Developing and implementing OODBMS that is based on object oriented programming paradigm.

Answer 5

There are no as such disadvantage of Relational database model . Relational DBMS define relationship between tables and also there is increased security. There can be a over head due to complexity in relations between tables and thus reduces throughput.

Answer 6

larger size

greater complexity

greater impact of system failure

more complex recovery procedures

Answer 7

The main disadvantage of hierarchical database is the rigid structure it possesses. This means that you cannot modify the database to suit current needs of the business.

Answer 8

The limitation of language is a disadvantage of relational data models. Developers are also required to recreate logic which may lead to mismatches in the system.

Answer 9

Greater search capabilities.