DBMS Definition and Meaning
According to ABBREVIATIONFINDER, SGBD, which stands for Systems management databases (in English database management system, abbreviated DBMS) are a type of software very specific, dedicated to provide an interface between the database, the user and applications that use it. They allow the data elements to be described with their structure, their interrelationships and their validations.
The general purpose of database management systems is to manage in a clear, simple and orderly way a set of data that will later become relevant information for an organization.
There are different objectives that DBMS must meet:
- Information abstraction. DBMS save users details about the physical storage of data. It does not matter if a database occupies one or hundreds of files, this fact is made transparent to the user. Thus, several levels of abstraction are defined.
- Independence. Data independence consists of the ability to modify the schema (physical or logical) of a database without having to make changes to the applications that use it.
- Consistency. In those cases in which it has not been possible to eliminate redundancy, it will be necessary to ensure that the information that appears repeated is updated consistently, that is, that all the repeated data are updated simultaneously. On the other hand, the database represents a certain reality that has certain conditions, for example that minors cannot have a driver’s license. The system should not accept data from an underage driver. In the DBMS there are tools that facilitate the programming of these types of conditions.
- Security. The information stored in a database can be of great value. The DBMS must guarantee that this information is secure from permissions to users and user groups, which allow granting various categories of permissions.
- Transaction management. A transaction is a program that runs as a single operation. This means that after an execution in which a failure occurs, it is the same that would be obtained if the program had not been executed. The DBMS provide mechanisms to program data modifications in a much simpler way than if they were not available.
- Response time. Logically, it is desirable to minimize the time that the DBMS takes to provide the requested information and to store the changes made.
- They provide facilities for the manipulation of large volumes of data (see objectives). Between these:
- Simplify the scheduling of consistency equipment.
- By managing the appropriate backup policies, they guarantee that the database changes will always be consistent regardless of whether there are errors correctly, etc.
- They organize data with minimal impact on program code.
- They drastically decrease development times and increase the quality of the developed system if they are well exploited by the developers.
- Usually, they provide interfaces and query languages that simplify data retrieval.
- Typically, it is necessary to have one or more people to administer the database, in the same way that it is usually necessary in installations of a certain size to have one or more people to administer the operating systems. This can increase operating costs in a company. However, this aspect must be balanced with the quality and reliability of the system that is obtained.
- If you have very little data that is used by a single user at a time and you don’t have to perform complex queries on the data, then it may be better to use a spreadsheet.
- Complexity: very complex software and the people who are going to use it must have knowledge of its functionalities to be able to take full advantage of it.
- Size: the complexity and the large number of functions that they have make it a large software, which requires a large amount of memory to run.
- Cost of additional hardware: The hardware requirements to run a DBMS are generally relatively high, so this equipment can cost a lot of money.
SGBD products available on the market
- PostgreSQL (http://www.postgresql.org Postgresql) BSD License
- Firebird based on InterBase version 6, Initial Developer’s PUBLIC LICENSE Version 1.0.
- SQLite (http://www.sqlite.org SQLite) Public Domain License
- DB2 Express-C (http://www.ibm.com/software/data/db2/express/)
- Apache Derby (http://db.apache.org/derby/)
- MariaDB (http://mariadb.org/)
- MySQL (http://dev.mysql.com/)
DBMS not free
- MySQL: Dual License, depends on the use. It is not known how long it will remain that way, since it has been bought by Oracle. However, there are 2 versions: a free one that would be equivalent to the “express” SQL server edition of Microsoft Windows, and a more complete paid version.
- Advantage Database
- Fox Pro
- IBM DB2: Universal Database (DB2 UDB)
- IBM Informix
- Interbase of CodeGear, a Borland subsidiary
- Microsoft Access
- Microsoft SQL Server
- Open access
- Progress (DBMS)
- Sybase ASE
- Sybase ASA
- Sybase IQ
- IBM IMS Hierarchical Database
DBMS not free and free
- Microsoft SQL Server Compact Edition Basic
- Sybase ASE Express Edition for Linux (Free Edition for Linux)
- Oracle Express Edition 10 (only runs on one server, limited capacity)