Data

Data is the information in a form suitable for processing by the computer, such as digital representation of numbers, text, graphic images or sounds.

Database

A database of collection of related information organized for rapid search and retrieval. Database can contain all types of data from an address list to students’ scores and grades. Ms Access is a database program that allows you to organize andmanipulates data in many different ways.

Database Management System (DBMS)

A database management system (DBMS) is a collection of programs that enables you to store, modify, and extract information from a database. There are many different types of database management systems, ranging from small systems that run on personal computers to huge systems that run on mainframes.

Examples of  Dbms Packages

DBASE

RBASE

ACCESS

DATACOM/DB

DB2

FOXPRO

IDMS

INFOMIX

INGRES

ORACLE

PARADOX

SQL SERVER

SYBASE

SYSTEM 2000

Examples of Database Applications

The following are examples of database applications:

• computerized library systems
• automated teller machines
• flight reservation systems
• computerized parts inventory systems

File

The collection of data that makes up a computerized database must be stored physically on some computer storage medium. The Dbms can then retrieve, update, and process this data as needed.

A file is a sequence of records.

Record

A database is a row of data in a database table consisting of a single value from each column of data in the table. The data in the column of a table are all of the same type of data, while the rows represent a given.

Field

A field is a data element that is an essential part of a data record. Withoutit, there would be no record in the database.

Key

This is a field in a record that holds unique data which identifies that record from other records in the file or database. Examples of keys are Account no. , product code, student’s admission no. etc. as an identifier, each key value must be unique in each record.

Types of keys in database include the following:

1. Super key
2. Candidate key
3. Composite key
4. Primary key

Tables

 A table in a ddatabase, alternatively known as relation, is a two-dimensional structure used to hold related information. A database consists of one or more related tables. it correspond to rows and columns

EXERCISE

Define The Folowing Terms

1. Database

2. Field/ column

3. Key

Advantages of a DBMS

Advantages of DBMS

The database management system has promising potential advantages, which are explained below: 

1. Controlling Redundancy: By having centralized database, repeated data that are not necessary can be avoided. It is not possible that all redundancy should be eliminated; however this redundancy can be controlled.

2. Integrity can be enforced: Integrity of data means that data in database is always accurate, such that incorrect information cannot be stored in database. In order to maintain the integrity of data, some integrity constraints are enforced on the database.

3. Inconsistency can be avoided: When the same data is duplicated and changes are made at one site, which is not propagated to the other site, it gives rise to inconsistency. So, if the redundancy is removed chances of having inconsistent data is also removed.

4. Data can be shared: A database can be shared by multiple applications in centralized DBMS as compared to file system, so now applications can be developed to operate against the same stored data.

5. Standards can be enforced : Since DBMS is a central system, so standard can be enforced easily may be at Company level, Department level, National level or International level.

6. Restricting unauthorized access: When multiple users share a database but access to data and information in the database will be controlled. For example, only authorized persons are allowed to access account office data.

7. Providing Backup and Recovery: A DBMS must provide facilities for recovering from hardware or software failures. The backup and recovery subsystem of the DBMS is responsible for recovery.

Disadvantages of DBMS 

The disadvantages of the database approach are summarized as follows:

1. Complexity : the functionality of a good DBMS makes it an extremely complex piece of software.

2. Size : The complexity of the DBMS makes it an extremely large piece of software, occupying many megabytes of disk space large amounts of memory to run efficiently.

3. Performance: with the DBMS written for many applications rather than just one, some applications may not run as fast as they used to.

4. Higher impact of a failure: The centralization of resources increases the vulnerability of the system

5. Cost of DBMS: The cost of DBMS varies significantly, depending on the environment and functionality provided.

6. Additional Hardware costs: The disk storage requirements for the DBMS may necessitate the purchase of additional storage space or even additional machines.

7. Cost of Conversion: this include; the cost of converting existing applications to new DBMS and hardware, cost of training staff to use the new systems and cost of specialist staff to help with conversion and running of the system.

Applications and Uses of MS-Access

1.  Microsoft Access Used For in Business  

Microsoft Access can be used for business For example, you want to make the data of financial report of your business.

2.  Microsoft Access Used For in Schools

MS Access can be used in administration and statistics. It can also be used for the teachers and students to make the schedules and time table

3. For Office

For office, there are many positions of people who often work with database. For examples are secretary, HRD, and financial planner.

4.  Microsoft Access Used For In The Workplace 

It can be used in some organizations for carrying out activities such as  are income and outcome report, activity plan and  reports. 

5. For Programmer

Programmers also often work with database. Ms Access is very useful for programmers to ease their activities related to programming.