AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Mdm basic concepts11/4/2023 Data dictionary or Metadata: Metadata is known as the data about the data. Constraints are defined while we are creating a table.ģ. Data Constraints: In a database, sometimes we put some restrictions on the table that what type of data can be stored in one or more columns of the table, it can be done by using constraints. Or we can say that it is a skeleton of the database that is used to represent the structure, types of data will be stored in the rows and columns, constraints, relationships between the tables.Ģ. Database Schema: It is a design of the database. To store and manage data efficiently in the database let us understand some key terms:ġ. ![]() In such a context the concept of data independence proves beneficial. This should not lead to redesign and re-implementation of the database. As databases continue to grow, there may be frequent changes to it at times. ![]() Since a database can be viewed through three levels of abstraction, any change at one level can affect plans at other levels. External Level(View Level): It is the level closest to users and is related to the way the data is viewed by individual users.Users at this level are not concerned with how these logical data structures will be implemented at the physical level. At this level, databases are described logically in terms of simple data structures. It also describes the relationships that exist between the data. Conceptual Level: This level of abstraction describes what data is concretely stored in the database.It describes how the data is stored concretely on the storage medium. Internal Level(Physical Level): The lowest level of abstraction, the internal level, is closest to physical storage.The different levels of the database are implemented through three layers: The complexity of databases is hidden from them which, if necessary, are ordered through multiple levels of abstraction to facilitate their interaction with the system. This means that the system does not disclose all the details of the data, rather it hides some details of how the data is stored and maintained. Database AbstractionĪ major purpose of a database is to provide the user with only as much information as is required of them. A database management system is an answer to all these problems as it provides centralized control of the data. However, this scheme has several major limitations and disadvantages, such as data redundancy (duplication of data), data inconsistency, maladaptive data, non-standard data, insecure data, incorrect data, etc. Many different application programs are written to extract the records and add the records to the appropriate files. In a typical file-processing system, permanent records are stored in different files. ![]() It may be possible to search the database to obtain answers to questions or information for planning purposes. It would permit only the retrieval of data but also the continuous modification of data needed for the control of operations. Therefore, a database is often thought of as a repository of information needed to run certain functions in a corporation or organization. The intent of a database is that a collection of data should serve as many applications as possible. The data is structured so as to provide the basis for future application development. ![]() A generic and controlled approach is used to add new data and modify and retrieve existing data within the database. It can also be defined as a collection of interrelated data stored together to serve multiple applications, the data is stored so that it is independent of programs that use the data. It maintains any information that may be necessary to the decision-making process involved in the management of that organization. A collection of data, commonly called a database, contains information about a particular enterprise. The database system is an excellent computer-based record-keeping system.
0 Comments
Read More
Leave a Reply. |