Question

11. Define the following terms showing in a table (only the first three show in
the table).
5
1. Relation
4. Query
2. Record
5. Reports
3. Field​

Answer 1

Answer:

Bit (Character) - a bit is the smallest unit of data representation (value of a bit may be a 0 or 1). Eight bits make a byte which can represent a character or a special symbol in a character code.

Field - a field consists of a grouping of characters. A data field represents an attribute (a characteristic or quality) of some entity (object, person, place, or event).

Record - a record represents a collection of attributes that describe a real-world entity. A record consists of fields, with each field describing an attribute of the entity.

File - a group of related records. Files are frequently classified by the application for which they are primarily used (employee file). A primary key in a file is the field (or fields) whose value identifies a record among others in a data file.

Database - is an integrated collection of logically related records or files. A database consolidates records previously stored in separate files into a common pool of data records that provides data for many applications. The data is managed by systems software called database management systems (DBMS). The data stored in a database is independent of the application programs using it and of the types of secondary storage devices on which it is stored.

6.2 File Environment and its Limitations

There are three principal methods of organizing files, of which only two provide the direct access necessary in on-line systems.

File Organization [Figure 6.2 & 6.3]

Data files are organized so as to facilitate access to records and to ensure their efficient storage. A tradeoff between these two requirements generally exists: if rapid access is required, more storage is required to make it possible.

Access to a record for reading it is the essential operation on data. There are two types of access: