Database servers

A database server is a server which houses a database application that provides database services to other computer programs or to computers, as defined by the client–server model.Database management systems frequently provide database-server functionality, and some database management systems (DBMSs) (such as MySQL) rely exclusively on the client–server model for database access (while others e.g. SQLite are meant for using as an embedded database).

Users access a database server either through a "front end" running on the user's computer – which displays requested data – or through the "back end", which runs on the server and handles tasks such as data analysis and storage.

In a master-slave model, database master servers are central and primary locations of data while database slave servers are synchronized backups of the master acting as proxies.

Most database applications respond to a query language. Each database understands its query language and converts each submitted to server-readable form and executes it to retrieve results.

Examples of proprietary database applications include Oracle, DB2, Informix, and Microsoft SQL Server. Examples of free software database applications include PostgreSQL; and under the GNU General Public Licence include Ingres and MySQL. Every server uses its own query logic and structure. The SQL (Structured Query Language) query language is more or less the same on all relational database applications.

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