data base for advances in information , base for advances in information systems
Database
Database management systems
The database management system manages three things related to the database, which are the data itself, and the database engine; Which allows accessing, modifying, or blocking data, in addition to the database schema , and all of these things aim to ensure the security of data, its reliability, and the ability to access it by more than one user at the same time , In addition to providing the appropriate tools for engineers and technicians to manage the database to the fullest.
Among the tools provided by the database management system for technicians and engineers that enable them to monitor the status and performance of the database, in addition to creating a backup of the data in it and the ability to retrieve it, and some database management systems provide automatic techniques for carrying out certain operations on databases such as restarting the system , And retrieving data, and creating a record of all transactions that took place in a specific period of time. Examples of some database management systems are: Oracle Database , Microsoft Access , MySQL and non-relational databases , PostgreSQL, and Microsoft SQL Server.
Benefits of use
- Data security.
- Techniques to enable multiple users to access data at the same time, in addition to setting priorities between them by locking the base from certain users .
- The possibility of restoring the system very quickly in the event of a malfunction or failure.
- Activity logging recording of various activities on the data.
- The ability to deal with it and access data simply through application programming interfaces .
Query languages
Query languages are programming languages that are used to retrieve data from databases and information systems by sending query sentences that are very similar to the English language . Specific data and retrieval from databases. Query languages can be used to create, modify, or retrieve data from DBMS. The Sequel language or SQL is an example of query languages. To retrieve all customer data in a company from a table called (customers) in the database, the following sentence (SELECT * FROM customers) is sent to the database management system.Types of databases
- Relational : was invented in 1970, in which data is stored in the form of tables containing at least one column that expresses the type of data, in addition to rows, and these are entries that contain specific data, the number of which is the same as the number of columns (categories) available For example, if the table consists of three columns, which are name, age, and height, then the entry “Name: Mark , Age: 20, Height: 170” can be added to this table. SQL is usually used in this type of database to deal with the data in it.
- Distributed database: The databases of this type are distributed in more than one place, that is, more than one computer device , so that the operations carried out on the data are dispersed or repeated in different places of the same network, and this type of database can be The data is homogenous; So that the distributed devices that contain the database are identical to each other in specifications (such as hardware, operating system , etc.), or heterogeneous ; So that the specifications of the devices used vary.
- Cloud : This type of database is designated and adapted for use in cloud environments , and this type is subject to expansion as desired (Scalability), in addition to the fact that the database remains available for continuous access to it.
- Non-relational (NoSQL): This type of database is designed to deal with a large amount of data, and the relational databases are not prepared to deal with it, and the (NoSQL) databases are more effective when you want to process a large amount of data that cannot be Arranging them according to a specific structure, or those that are distributed on several virtual servers .
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