Found 338 Articles for DBMS

Let’s discuss flat and database definition before understanding the difference between flat files and databases.Flat filesA flat file contains records which have no structured interrelationship. They are typically called as a text file, where all word processing, structure characters and markup have been removed. A flat file represents a table with a single record per line. Generally, it is a type of database that stores data in a plain text format.DatabaseThe related information when placed in an organized form that makes a database or an organized collection of related information is called a database.For example − Dictionary, Telephone directory etc.DifferencesFollowing ... Read More

DatabaseDatabase represents a data structure comprised of tables, schemas to store user and system information. It provides SQL to Create, Read, Delete and Update its records. DBMS, Database management systems manages a database. Usually Database administrators modifies the sensitive data. A database follows client-server model architecture.BlockchainBlockchain represents a chain of blocks analogous to records in database. This chain grows as blocks are added to it during operations. These blocks contains link to previous block using cryptographic hash of address of the block, timestamp and transaction data. A block once added to the blockchain cannot be modified by design. A Blockchain ... Read More

In database management systems (DBMS), there are two terms namely mirroring and replication which are related to copying of data. Mirroring is defined as the process of copying a database to another location, while replication is defined as the process of copying the database objects from one database to another. Read this article to learn more about mirroring and replication and how they are different from each other. What is Mirroring? Mirroring refers to keeping a backup database server for a master database server. If for some reason, the master database is down, then the mirror database can be used ... Read More

Anybody dealing with databases must comprehend the distinction between DDL and DML commands because it has an impact on how data is saved, accessed, and modified. A collection of commands called DDL are used to specify a database's structure. Database objects including tables, views, indexes, and constraints can be created, modified, and deleted using these commands. DDL statements specify how the data is arranged and accessed rather than altering the data that is stored in the database. DML, on the other hand, is a set of instructions used to work with the data that is kept in the ... Read More

A DBMS (Database Management System) is a software that is used to manage a database. It is used to create, update, delete and maintain a database and it provides controlled access to data. An RDBMS (Relational Database Management System) is a type of DBMS that is based on the relational model of data. It can be regarded as an enhanced version of DBMS. Read this tutorial to find out more about DBMS and RDBMS and how they are different from each other. What is a DBMS? DBMS stands for Database Management System. A DBMS stores data in the form of ... Read More

A relationship is an important part of any Entity relationship diagram as it shows the relation between two different entities. In an n - ary relationship, the n shows the number of entities in the relationship. It can be anything but the most popular relationships are unary, binary and ternary where the number of entities respectively are one, two and three.More information about Unary, Binary and Ternary relationships is as follows −Unary RelationshipWhen there is a relationship between two entities of the same type, it is known as a unary or recursive relationship. This means that the relationship is between ... Read More

A centralized database is stored at a single location such as a mainframe computer. It is maintained and modified from that location only and usually accessed using an internet connection such as a LAN or WAN. The centralized database is used by organisations such as colleges, companies, banks etc.As can be seen from the above diagram, all the information for the organisation is stored in a single database. This database is known as the centralized database.AdvantagesSome advantages of Centralized Database Management System are −The data integrity is maximised as the whole database is stored at a single physical location. This ... Read More

Database SecurityDatabase security has many different layers, but the key aspects are:AuthenticationUser authentication is to make sure that the person accessing the database is who he claims to be. Authentication can be done at the operating system level or even the database level itself. Many authentication systems such as retina scanners or bio-metrics are used to make sure unauthorized people cannot access the database.AuthorizationAuthorization is a privilege provided by the Database Administer. Users of the database can only view the contents they are authorized to view. The rest of the database is out of bounds to them.The different permissions for ... Read More

Locks are an integral part to maintain concurrency control in DBMS. A transaction in any system implementing lock based concurrency control cannot read or write a statement until it has obtained the required locks.There are two types of locks in Lock based protocols. These are:Binary Locks - These can only be in one of two states, locked or unlocked.Shared/Exclusive Locks - Shared locks are acquired when only read operation is to be performed. Shared locks can be shared between multiple transactions as there is no data being altered. Exclusive locks are used when write operation is performed. Only the transaction holding the ... Read More

In a distributed database management system, the database is not stored at a single location. Rather, it may be stored in multiple computers at the same place or geographically spread far away. Despite all this, the distributed database appears as a single database to the user. A diagram to better explain this is as follows:As seen in the figure, the components of the distributed database can be in multiple locations such as India, Canada, Australia, etc. However, this is transparent to the user i.e the database appears as a single entity.Types of Distributed Database Management SystemThe following are the types ... Read More