Information retrieval, DBMS and search engines

Information retrieval, DBMS and search engines

Introduction

Database Security contains two meanings: the first layer is the system is running security system safe operation of the usual threats are as follows, network criminals through a network, LAN, and other ways through the invasion of the computer system does not start properly, or overload the machine running a large number of algorithms, and turn off the CPU fan, CPU overheating burn and other destructive activities.

The second layer is the information systems security, system security is usually the threats are as follows hacker intrusion on the database, and steal the information you want. Database system security features for data, including data independence, data security, data integrity, concurrency control, fault recovery. Management system is responsible to avoid concurrent access to the database. This registration also contains information relevant to the recovery of the database, if a failure thereof or a system crash. Although this mechanism does not prevent unauthorized access, is a deterrent to potential attackers, allowing also found weaknesses in security mechanisms. In addition to all these mechanisms, the physical medium that is stored on the database may be protected cryptographically. Also backups can these well defended against attacks.

Initially we will explain DBMS, and then the key differences between DBMS and text retrieval systems. Then we will discuss about the text search functionality of a DBMS (either commercial or open source). Describe it in as much detail as you can, including the query language by giving illustrative examples. Compare this functionality to a search engine.

Discussion

A database management system (DBMS) provides different tools, created with which one or more databases; data can be filled and maintained. A DBMS typically has at least one user interface, and can only manage one or more databases in sequence or in parallel. Furthermore, there are (explicitly or implicitly) rules as to who and at what time accesses and changes rights to the data. Finally, hedging strategies/backup procedures defined and are performed regularly.

Each user interface consists of either different masks (SQL Enterprise Manager) and offers users a way to directly receive commands. These will be sent to the DBMS and this runs against the current database. The language could have been used for this purpose by the manufacturer of the DBMS developed freely. In fact is supported by most relational DBMS Structured Query Language (SQL) with any custom extensions.

Main Features of DBMS

The main features of the database system:

Data structures: the database system to achieve the structure of the data as a whole, this is one of the main features of the database, database systems and file systems essential difference. 

The sharing of data is high, low redundancy, and easy expansion: the database data is no longer an application-oriented, but for the entire system, it can be multiple users, multiple applications in many different languages shared use. Since the data for the entire system is structured data, not only can multiple applications to share use, and easy to add new applications, which makes the database system flexibility, easy to extend. 

Data independence: data independence includes the ...