Database management system
In computer, a Database Management System (abbreviated DBMS) is a software system designed to allow the efficient creation and manipulation of database (ie collections of structured data) usually by multiple users. The DBMS play a key role in many computer applications, from accounting, human resources management and finance to contexts Techniques such as network management or phone. If the DBMS were common in the past mainly in the major companies and institutions (who could afford the financial commitment resulting from the purchase of major infrastructure hardware necessary to create an efficient database system), today their use is widespread in almost any context. The expression enterprise application, in computer jargon that relates to business-related applications to businesses that use them, implies almost by definition "the presence of one or more databases managed by one or more of the DBMS.
database theory, and the DBMS, is always been one of the most solid and important strands of ' computer.
A DBMS is different from the general concept of application on database, as it is designed for multi-user systems. For this purpose, rely on the DBMS kernel that natively support the multitasking and network connections in . A typical application for the management of the database does not include, in fact, these features, but relies on operating system to allow the user to benefit from it advantages.
database theory, and the DBMS, is always been one of the most solid and important strands of ' computer.
A DBMS is different from the general concept of application on database, as it is designed for multi-user systems. For this purpose, rely on the DBMS kernel that natively support the multitasking and network connections in . A typical application for the management of the database does not include, in fact, these features, but relies on operating system to allow the user to benefit from it advantages.
A DBMS may consist of a set of very complex software programs that control the organization, storage and retrieval of data (fields , records and archives) in a database. A DBMS also controls the security and integrity of the database. The DBMS accepts requests for data from the application program and train the operating system for the transfer of appropriate data.
data security system prevents unauthorized users to view or update the database. Through the use of passwords (passwords), users are allowed access to the entire database or a subset of it: in the latter is called a subschema. For example, a database of employees may hold all the data on a single entity, but a group of users can be authorized to view only the data on salary, while others may be allowed to see only the information concerning his work history and health status.
The DBMS can maintain the integrity of the database allowing multiple users to simultaneously edit the same record (block of the record). The database can prevent the introduction of two duplicate records, for example, may be blocked from entry into the database of two customers with the same ID number (key field). The set of rules that determine the integrity and consistency of a database are called referential integrity constraints. In this regard, see the so-called property " ACID.
An information system consists of business entities (customers, employees, vendors) and activities (orders, payments, purchases, etc.).. The design of the database ( database design) is the decision-making process on how to organize this data into record types and how each type of record relates to others. The DBMS should mirror the structure of data organization and effectively manage the various transactions.
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