All human activity is inextricably linked with a variety of information directories and databases.Library registry, notebook, address in the mobile phone or tablet - this is not a complete list of structured information, which we use.But computers like accuracy and give the definition.
So, database (DB) - set of logically related data, information describing the state of the objects in a variety of subject areas and processed by computers.
database management system is a software and language environment for creating, managing and processing information databases.Destination database:
- work with databases on the outside (disks, tapes, and so on. D.) And RAM;
- sharing users;
- change control, backup and restore databases;
- provide language access for information processing;
- utilities to create, modify and manage databases.
Simply put, the database determines the method of storing information , a DBMS provides means for its processing .Advanced database management system is divided into system
Relational Management System
Since the advent of computer databases have been many models of their work, but relational model was the most universal.It is a related set of information tables, ensures the integrity and minimal data redundancy.Tabular model proved to be applicable to the majority of subject areas, and the market is a relational database management system began to develop rapidly.The figure shows an example of the structure of a relational "database of students."
All RDBMS supports ANSI SQL standard and the basic principles of the relational model, which enables applications to run on different databases.In addition, large databases have their own additions expand SQL.Examples of database management systems for large projects - is Microsoft SQL Server and ORACLE.
relational model successfully used in the development of Internet projects.Examples are the MySQL and PostgreSQL.
technology NoSQL
Increasing volumes of information and complexity of the relationship has led to the emergence of new database management systems.Information has ceased to be independent of each other, and sometimes even impossible to strictly describe its structure.Relational databases are no longer able to cope with such tasks.This led to the emergence of a new type of database information and management systems, collectively known as NoSQL («no SQL»).
main category database NoSQL:
- «key-value» .The most popular database - Redis, Voldemort, Tokyo Cabinet and Dynomite.
- Clones database BigTable. developed Google's internal use search engine.Officially BigTable is not offered, but there is a database based on it.It Hadoop, Hypertable and Cassandra.
- document-oriented. most popular Berkeley DB XML, MongoD, eXist and CouchDB.
- Base on the theory of graphs. Used Neo4j, Sones graphDB and AllegroGraph.
Future of DBMS
market database management systems continues to grow and more and more inclined to use NoSQL-making.Of course, the "classical» SQL sold a huge amount of software systems of varying complexity, and behind it the market giants such as Microsoft and ORACLE.But with certainty we can assume that NoSQL in the coming years will significantly oust leaders in the development of complex information systems.
