databases Flashcards
(38 cards)
define ‘database’
A database is an organised collection of data that is either either stored electronically or manually.
what is ‘data’
Computer data is information processed or stored by a computer
Data is defined as unprocessed information.
Information is data that has been organised and communicated meaningly. Normally, data is converted into information, and information is converted into knowledge.
what is a ‘manual database’
They are hard copies of databases storing information such as phone/address books or manila folders in alphabetical order (each manilla folder is known as a file).
what is an electronic database
These are also forms of databases but are digital files stored on a computer or electronic device.
what are the two forms of electronic databases
they can be closed (Purchased with data already entered about a particular topic) or shell/open databases (A program that allows users to develop their own data).
what are the types of electronic databases
Types of electronic databases include flat/flat-file systems (Small but stores thousands of records in a single table/file), or Database Management System (DBMS) (Software that controls very large databases made up of several tables/files that can link together).
what are flat-file systems
Flat file systems are non-relational databases, meaning information is placed in field categories and can be sorted but cannot be extracted or linked to other database files.
what are DMBS’
DBMS are relational databases and be connected to other databases, this is called a relational database. They can be divided into two categories (single user, or multiuser)
what is an online database
These are files accessible over the internet or networks (e.g google, youtube)
list some advantages of a manual database
- does not depend on the internet to work
- correcting entries are easier
- less expensive
- no duplicates
- do not require previous experience
list some disadvantages of a manual database
- Information must be found by hand rather than electronically (electronic databases can pull information from other areas being much faster)
- Manual databases are vulnerable to damage, destruction and theft in ways that digital databases are not.
list some advantages of an electronic database
- Helps record business transactions (income and expenses, payments to workers, and stocks)
- Efficient way to keep financial records and requires less storage space.
- Allows you to back up records and keep them in a safe place in case of fire or theft.
list some disadvantages of an electronic database
- An online database can be hacked and can easily receive viruses and other malware.
- The cost of operating and developing a database for online application and operation can be fairly expensive.
list some examples of databases in real life
- Telephone books
- Television
- Online Reservation Systems
- Files on your computer hard drive
- Record papers
what is the main purpose of a database?
The main purposes of databases are to keep records organised for fast, efficient retrieval. They are also used to analyse information and make informed decisions.
what are some records that could be kept?
School: Students and staff
Library: Books and borrowers
Shop: Stock and employees
what do databases do?
Databases are used to transform
Data -> Information -> knowledge -> action
what are the main components of a database?
The four main components of a database allow data to be input and output/viewed in different ways. These include
- Tables
- Forms
- Queries
- Reports
what is a table?
A table stores individual facts or data in an organised way.It is made up of several components that form a hierarchy in which the most important level is at the top. e.g tables consisting of employee data
what is a form?
User-friendly interfaces to enter/view data
what is a querie
Queries are a way of searching for and compiling data from one or more tables. Running a query is like asking a detailed question of your database as you are defining specific search conditions to find exactly the data you want. By using queries you could possibly find out information you would not be able to gain from looking at a table. It is one of the main components of a database. For example, your query could be ‘customers living in NSW’ and then it would order the query so that you can easily retrieve the information of only the people who live in NSW.
what is a report
Reports offer you the ability to present your data in print. Reports are useful, because they allow you to present components of your database in an easy-to read format. Reports are also used to make informed decisions or to take action. It is one of the main components of a database. For example, all of your databases fields and information would all be formatted onto a page/s where you can then easily print it and view the information.
what do you need to consider when entering data?
you need to consider
- Consistency
(all data in one field must be of the same type, e.g must be entered the same way 28/07/16)
- Simplicity
(data entry should be kept to a single character or as small as possible, e.g. using codes to simplify words M or F instead of Male and Female) - Accuracy
(Data should be verified to ensure it is entered correctly, e.g. fields should prevent forms of unacceptable entry such as numbers where letters are expected) - Currency
(Data should be kept up to date, e.g. a change in address should be changed abruptly) - Understandable
(Field names should make sense to any user, e,g, surname is meaningful, field1 is not)
what is a field?
A field is a component of a table that contains data about one section of reach record such as alphabetic, numeric or alphanumeric data. For example, if you had first name as a table then your field is subdivided into the list of first names like John.
