The key is unique for every lock. Similarly, those attributes which are unique for every entity in a single table, are known as key attributes. Keys are nothing else only the unique attributes associated with every entity. Keys are useful in dbms for various reasons such as data integrity, efficient data retrieval, data consistency, data …
In today’s era Network or Internet is used to send and receive data worldwide. As we know the network is a complex structure consisting of lots of computers and networking devices. The system which seeks data is known as the Client and the system which provides the data is known as Host. Also, we know …
The Internet is not that much easy as we think. It is a vast and massive bunch of hardware devices interconnected all over the internet. These devices are assembled in groups and then these tiny groups are connected with each other, and then these massive groups are connected with each other and the cycle goes …
Decomposition means dividing a large and complex table into multiple small and easy tables. This removes redundancy, anomalies, and inconsistency in a database. This is the first stage of normalization. Suppose we have a relational schema R, in which we have attributes as given below: A1, A2, A3…………An So R = {A1, A2, A3…………An} If …
The degree of relationship means the number of entities associated with a relationship in a relational model. Based on the number of entities associated we have the following degree of relationships. Unary Relationship In this only a single entity is associated in a relation. It is mostly used to represent the recursive relationship, which means …
A Database is a very complex mechanism to handle and control a large amount of data. As we all know the overall design of the database is known as database schema which is further divided into three categories as given below: The database or relational schema looks quite simpler and effective from the top but …
This is a high-level programming language, which is used by database users to access the database. This is also called non-procedural language because just like other programming languages it does not follow any fixed procedure or sequence for execution. Instead, it allows users to just pass on the commands in simple English text that follow …
Fourth Generation Language (4GL) – Advantages & Disadvantages Read More »
Cryptography is the study of data security through Encryption technique, which describe the encryption process and techniques used. A cipher is an algorithm which is used to encrypt or decrypt the data. Plain text is converted in cipher text with help of this. The transforming process is performed using a key. This key is like …
