Database essay

A database essay

A database is an organized collection of data. The data are typically organized to model aspects of reality in a way that supports processes requiring information. A database is a repository of data. A database is simply a collection of organized information, usually as a set of related lists of similar entries. The data is often organized so that it is easily accessible. Formally, "database" refers to the data themselves and supporting data structures. Databases are created to operate large quantities of information by inputting, storing, retrieving and managing that information.

Databases are set up so that one set of software programs provides all users with access to all the data. A database consists of a number of interrelated tables. Each table has a number of records which are used to represent real world objects. Each record has a number of fields which are data items used to specify a characteristic of the record. Each record in a table must be uniquely identified by a particular value in one of its fields and the field is called a primary key. For instance a person’s name may be enough to uniquely identify this person, but then again, many people can have the same name. Sometimes, we chose to assign unique numbers to people in order to uniquely identify them (e.g., employee number, social insurance number, student number etc…).We may also use more than one field to identify a record in a table and a set of keys are used which form a Composite key.

To be able to work with databases we need a database management system (DBMS) which is a computer software application that interacts with the user, other applications, and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases. Well-known DBMSs include MySQL, Microsoft SQL Server, Oracle, SAP and IBM DB2. A database is not generally portable across different DBMSs, but different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS. Database management systems are often classified according to the database model that they support.

A DBMS has an advantage over the traditional file system in that it there is: Flexibility: Because programs and data are independent, programs do not have to be modified when types of unrelated data are added to or deleted from the database, or when physical storage changes.Fast response to information requests: Because data is integrated into a single database, complex requests can be handled much more rapidly than locating data separately. In many businesses, faster response means better customer service. Multiple access: Database software allows data to be accessed in a variety of ways (through various key fields), by using several programming languages (both3GL and nonprocedural4GL programs). Lower user training costs: Users often find it easier to learn such systems and training costs may be reduced. Also, the total time taken to process requests may be less, which would increase user productivity. Less storage: Theoretically, all occurrences of data items need be stored only once, thereby eliminating the storage of redundant data. System developers and database designers often use data normalization to minimize data redundancy.

The logical structure of a database is determined by a database model which also fundamentally determines in which manner data can be stored, organized, and manipulated. The most popular example of a database model is the relational model, which uses a table-based format. Other logical models include entity relationship model, network model, object model, document model and hierarchical models.

There three basic operations which can be carried out on databases by a DBMS and they include design, data entry and queries. Design entails creation of a database by defining tables which specifies what is to be stored. Data entry involves entering all data to tables once they have been created. Queries is asking questions about data for retrieval and update. A query is the question (or command) that we send to the database in order to select and view the data that we want to see.

Databases can be classified in many ways for instance the type of content for example bibliographic, document-text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance. A third way is by some technical aspect, such as the database structure or interface type. Different types of databases include: In-memory database, active database, deductive, cloud, data warehouses, distributed, embedded, federated, graph, hypertext database, knowledge base, terminology oriented, real time and unstructured data databases.

In conclusion database is much more than just a list or table. It gives you true command of your data, enabling you to retrieve it, sort it, analyze it, summarize it, and report results in moments. It can combine data from various files, so that you never have to enter information twice. It can even make data entry more efficient and accurate. Other benefits of databases are making information is easy to access at any time. It's more easily retrievable. Many people can access the same database at the same time. Improved data security. Reduced data entry, storage, and retrieval costs. However Database systems are complex, difficult, and time-consuming to design. Initial training required for all programmers and users. Suitable hardware and software start-up costs. A longer running time for individual applications.