Hierarchical Database System:Â The previous system FMS drawback of accessing records and sorting records which took a long time was removed in this by the introduction of parent-child relationship between records in database. The origin of the data is called the root from which several branches have data at different levels and the last level is called the leaf. The main drawback in this was if there is any modification or addition made to the structure then the whole structure needed alteration which made the task a tedious one. In order to avoid this next system took its origin which is called as the Network Database System.
Network Database System:Â In this the main concept of many-many relationships got introduced. But this also followed the same technology of pointers to define relationships with a difference in this made in the introduction if grouping of data items as sets.
Relational Database System:Â In order to overcome all the drawbacks of the previous systems the Relational Database System got introduced in which data get organized as tables and each record forms a row with many fields or attributes in it. Relationships between tables are also formed in this system.
ï® Data collection, database creation, IMS (hierarchical database system by
IBM) and network DBMS
ï® Relational data model, relational DBMS implementat ion
ï® RDBMS, advanced data models (extended-relat ional, OO, deductive, etc.)
ï® Application-orient ed DBMS (spatial, scientific, engineering, etc.)
ï® Data mining, data warehousing, multimedia databases, and Web
ï® Stream data management and mining
ï® Data mining and its applications
ï® Web technology (XML, data integration) and global information systems
The "relational" data model
The "relational" data model, by Ted Codd in his
landmark 1970 article "A Relational Model of Data
for Large Shared Data Banks", was a major advance
ï® The relational model unified data and metadata so
that there was only one form of data representation.
ï® A non-procedural data access language based on
algebra or logic.
ï® It was easier for end-users to visualize and
understand than the pointers-and-records-based
ï® Programs could be written in terms of the "abstract
model" of the data, rather than the actual database
design => programs were insensitive to changes in
the database design
Relational Database Management System or RDBMS was developed in 1970. It was introduced by Edgar F. Codd who was working with IBM. Basically, RDBMS is a developed form of some popular database systems like hierarchical system etc.
Though this database system was developed originally by IBM, many other stalwarts related to IT came forward with the versions of their own. This led to a competition, between various vendors, to make it more user-friendly and efficient. As a matter of fact, this competition only added to make it simpler and more advanced.
RDBMS is most widely used database system as far as data storage is concerned. Out of many RDBMS products available in the market, its most famous products are Oracle, D2B family by IBM, Microsoft's access etc. Some other famous products are Foxbase, Sybase, Informix etc.
The relational database management system uses Standard Query Language(SQL). The database system keeps all the information in a tabular form. This tabular form uses certain data values to define and describe the data. This database system also ensures that no information in a specific column in repeated.
RDBMS consists of one or many tables. These tables are made of interrelation between many columns and rows. The developers use set theory. This set theory puts these data in these columns and rows. These columns and rows, with data full in them, help to do certain data related operations.
RDBMS has been regarded by many as a very simple but advanced database system. Its simplicity makes its more user-friendly. Its easy-to-use features make it more productive. To make it simpler, simple tables are used by developers. Hence, the processing and understanding of data becomes easier. It also inspire easy communication of data and their transfers.
SQL has always remained too easy to learn by a database operator or user . As RDBMS uses SQL, it becomes lot easier for anybody to master this system at a great speed. Thus, this learning ease makes it immensely productive.
Further, it shows its great inability to store any information in form of an image or pictures. Moreover, a user can't store any video reel or any document in form of audio. In short, nothing sort of digital things could be loaded in this system.
However, the drawbacks and limitations are too less to be counted. These few shortcomings of RDBMS stand nowhere when we have a thorough look upon its vast and effective use and operations. No doubt, it was no less than a wonder when introduced almost forty years ago and interestingly, it is a wonder still.
Stationary Supplies is a company that sells stationary products to customers. Stationary Supplies allows their account customers to place orders over the telephone and delivers the required products to the customers' premises. This is possible for account customers because the company keeps information about these customers in a database, including an identifier, the customer name, phone number and delivery address.
When an order is phoned through by a customer the company records order details, and in-particular the date of the order. Stationary Supplies keeps a database of information about their products, and when orders are received a record of the quantity of a product included in the order is recorded. An order may contain a number of different products.
At first, database management systems are very crude, as there was always a memory problem with the earlier electronic computers. In fact, Bill Gates was quoted as saying in 1981 that 640K memory ought to be enough for anybody. Ha!
Around the 1960s, the earliest of electromagnetic database storage was used only by those who could afford it, because of its extremely high expense. In fact, whereas today databases are used for research purposes, at this time computers were themselves considered a research project.
It wasn't until the 1970s, when memory was able to be increased and component prices began to decrease, was there any real headway with database management systems. It was at this time that a number of different problems started coming up, as related to information management on the computers. With all these problems surfacing, a solution was needed.
In the 1980 all the major vendors who sold hardware systems started incorporating database management systems into their computers for a systematic solution.
At first, these database management systems were very specific to the computer and to the user. IBM was one of the leaders in this category, but soon many clones and competitors entered into the marketplace, all at varying price points with different and alternative solutions.
With the advent of the 90s, the shift turned from having an accurate database management system, to having one that was easily maintainable. This is because memory capacity started to grow, as well as the creation and spread of information. This is when some of the more sophisticated database management systems at the market.
Currently, the focus is on completely automating most of the database management administration.