Database


A database is an organized collection of information. it's the gathering of schemes, tables, queries, reports, views and other objects. the info is usually organized to model aspects of reality during a way that supports processes requiring information, like modelling the provision of rooms in hotels during a way that supports finding a hotel with vacancies.

Database Management System DBMS


Database Management System (DBMS) | What is DBMS? 

Database management systems are software programs (application) that interact with the user, other applications, and so the database analyze data. A general purpose DBMS is supposed to allow the definition, creation, update, querying, and administration of database. PostgreSQL, MySQL, Microsoft SQL Server and Oracle are well-known DBMSs. A database isn't generally portable across different DBMSs, but different DBMS can interoperate by using standards like SQL to permit one application to figure with quite one DBMS. direction systems are often classified per the database model that they support; the foremost popular database systems since the 1980s have all supported the relational model as represented by the SQL language. Sometimes a DBMS is loosely cited as a 'database.

Database Schema :-

A database schema of a database system is it structure described in a very formal language supported by the management system (DBMS) and refers to the organization of knowledge as a blueprint of how a database is made (divided into database tables within the case of Relational Databases). The formal definition of database schema may be a set of formulas called integrity constraints imposed on a database. These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible within the same language. A database may be considered a structure in realization of the database language. The states of a created conceptual schema are transformed into a specific mapping, the database schema. This describes how globe entities are modeled within the database. A database schema specifies, supports the database administrator's knowledge of possible applications, the facts which will enter the database, or those of interest to the possible end-users.The notion of a database schema plays the identical role because the notion of theory in mathematical logic. A model of this “theory” closely corresponds to a database, which may be seen at any instant of your time as a mathematical object. Thus a schema can contain formulas representing integrity constraints specifically for an application and so the constraints specifically for a form of database, all expressed within the identical database language. Computer database, the schema defines the tables, fields, indexes, relationships, views, packages, functions, procedures, queues, triggers, types, sequences, materialized views, database links, and other elements. Schemas are generally stored during a knowledge dictionary. Although a schema is defined in text database language, the term is typically accustomed hash out with a graphical depiction of the database structure. In other words, schema is that the structure of the database that defines the objects within the database. In an Oracle Database system, the term "schema" contains a rather different connotation.

Physical Schema:-


Physical schema could be a term utilized in data management to explain how data is to be represented and stored (files, indices, et al.) in external storage employing a particular management system (DBMS) (e.g., Oracle RDBMS, Sybase SQL Server, etc.).

Logical Schema:-


A logical schema could be a data model of a selected problem domain expressed in terms of a specific data management technology. Without being specific to a specific management product, it's in terms of either relational tables and columns, object-oriented classes, or XML tags. this can be as critical a conceptual data model, which describes the semantics of a corporation without regard to technology, or a physical data model, which describes the actual physical mechanisms wont to capture data in an exceedingly medium. The next step in creating a database, after the logical schema is produced, is to form the physical schema.




Type of Database Management System(DBMS)

  1. Hierarchical databases
  2. Network databases
  3. Relational databases (Rdbms)
  4. Object-oriented databases
  5. Graph databases
  6. ER model databases
  7. Document databases
  8. NoSQL databases

Database Management System Software | Dbms Software

  1. Microsoft SQL Server
  2. PostgreSQL
  3. My SQL
  4. Oracle RDBMS
  5. Microsoft Access