1. Databases

2. Learning Outcomes
LO1 Be able to describe and analyse a flat file database. LO2 Explain what verification and validation is. LO3 Apply validation to a database and verification to the real world.

3. Starter
How does Google work? First person= what are the different file organisation types used by databases? Second person= which file organization type is used by Google and how does it work? First Person = Why it isn’t the others?

4. Flat File Databases
A Flat File Database is a Database consisting of only one table. Simple, logical and useful for small sets of data Seems logical at first but do you really want to have to input all this data every time a pet has an appointment? There would also be more risk of mistakes.
Scenario- This is a database a vet may use.
When setting up a database you choose between either flat file or relational (to be talked about later).
Take a database that a vet might use. In our example on the right, there is data about the owner of the pet i.e. name, address, phone number, there is data about the pet - name, type of animal, date of birth, and there is also data about any appointments the pet has.
This might seem pretty logical at first. But think about it, is it really as good as it seems? Every single time the pet has an appointment, the customer's title, surname, street, town, county, and phone number have to be entered. Also, the pet's name, type and d.o.b. also have to be entered. That would get fairly tedious having to enter so much data each time and there would be a great risk of making a mistake (Garbage In, Garbage Out - GIGO).
Can be set up in a spreadsheet!!!
Businesses such as one dealing with online sales where details of customers, products, suppliers, and orders, all need to be stored and organised need a more carefully planned database than this simple flat file vets appointments database.

5. Data Redunancy
Data redundancy: the unnecessary repetition of data. This inevitability leads to complex processing problems because each instance of the repeated data has to be updated. This is inefficient and will probably lead to mistakes.
The use of the Flat File database will lead to data redundancy.
Give second example:
Address book used for orders. Its ok if the person just orders one item but should the same person order multiple items you would have name, dob, address, postcode etc repeated multiple times in diff records.
Note- if a customer changed their name or address you would have to go back and change every occurrence of that customers details for each order.

6. Data integrity, Validation and Verification
Key Definitions: Data integrity= The state of data being as it should be, reflecting reality. Validation= The process of checking data as it is input to ensure that it is reasonable. Verification= The process of checking that data is true or correct
Data redundancy is a way in which data integrity can be compromised. If data is entered incorrectly integrity is lost

7. Validation: Checking is done by data handling software and it can be set up to reject any data that does not conform to specific rules.
Come up with a mnemonic for validation techniques
Task: Pupils research how validation checks can be carried out!
Task: Create mnemonic

8. Task: Which Validation check would be appropriate?
Task: Students are to say which data validation technique would be appropriate for each field.

9. Verification
Validation cannot make sure data that you enter is correct, it can only check that it is sensible, reasonable and allowable.
Methods:
Checking data onscreen in comparison to the original documents.
Entering the data twice.
Printing out a copy of the data and comparing it to the original paper document.

10. Its quicker to enter data by machine, there are numerous ways data can be automated.
Barcodes
Magnetic Strips
OCR (optical character recognition)
OMR (optical mark recognition)
RFID (radio frequency identification)
Smart Cards
Task pupils to write what each is after explanation along with examples!
Barcode: Scanning the data replaces typing. You can then edit the scanned data, accept it by hitting the enter key, or whatever else you deem appropriate. This is the classic case of keyless data entry.
Magnetic strips: are built into many plastic cards such as debit or credit cards and personal identity cards. The magnetic strip on the back of the card can hold the personal details of the card owner and, with the necessary PIN, will allow access to secure information, eg bank account details. Data stored on the strip is scanned and input into a computer system by a magnetic stripe reader.
OCR: It is a technology that recognises and captures alphanumeric characters on a computer at high speed. It reduces the data entry time and increases its accuracy when compared to the use of manual data entry operators. EXAMPLE office of national statistics may use OCR to scan questionnaires and then store the data.
OMR: recognises marks on paper for instance when you do multiple choice tests the computer marks them.
RFID: There are a lot of interesting ways to use RFID products in the medical field. However now that the tags, themselves, can be made small; pharmaceuticals, lab samples, wristbands and other medical equipment can be tracked and traced, and data entry can be automated. Thus, RFID products in the medical field are aiding in the elimination of medical mistakes.
A smart card: typically a type of chip card, is a plastic card that contains an embedded computer chip–either a memory or microprocessor type–that stores and transacts data.

11. Plenary
What is the difference between verification and Validation, give examples?
Name 3 data entry procedures and describe them.
What is a flat file database?