* Database is a program that lets you input and manage data.
When you store data to your computer, the DBMS then will play its role. It will make a data structure to your data you just enter. Every data you stored to your computer has there own respective structure. After having the structure, the DBMS then will place your data with its structure to a container which is called as database. In database, all your data are well arranged and managed.
B. Define how each of the following fit and function within the framework of relational DBMS systems:
1. Key Fields - keys that are used in database.
- is a field or set of fields of a database (typically a relational database) table which together form a unique identifier for a database record (a table entry). The aggregate of these fields is usually referred to simply as "the key". Key fields also define searches.
2. Database Records - are data stored in database.
- also called a record or tuple—represents a single, implicitly structured data item in a table. In simple terms, a database table can be thought of as consisting of rows and columns or fields. Each row in a table represents a set of related data, and every row in the table has the same structure.
3. Data Queries - used to show data in many different ways.
- is a form of questioning, in a line of inquiry.
4. Data Types - are data that the DBMS can handle.
- (or datatype) in programming languages is a set of values and the operations on those values.
5. Data Forms - used to show data through user-friendly interface.
- are applicable to individual tables; to say that an entire database is in normal form n is to say that all of its tables are in normal form n.
6. Tables/database files - used to input and manage data.
- is a set of data elements (values) that is organized using a model of vertical columns (which are identified by their name) and horizontal rows. A table has a specified number of columns, but can have any number of rows. Each row is identified by the values appearing in a particular column subset which has been identified as a candidate key.
Table is another term for relations; although there is the difference in that a table is usually a multi-set (bag) of rows whereas a relation is a set and does not allow duplicates. Besides the actual data rows, tables generally have associated with them some meta-information, such as constraints on the table or on the values within particular columns.
The data in a table does not have to be physically stored in the database. Views are also relational tables, but their data are calculated at query time. Another example are nicknames, which represent a pointer to a table in another database.
7. Relationships (Table Linkage) - used to show data form one table to another through linking.
- is based on the relational model as introduced by E. F. Codd. Most popular commercial and open source databases currently in use are based on the relational model.
