Topic 4: Database Flashcards
What is a database
A database is a collection of related or structured information held on a computer (e.g. doctor’s records, school roll etc.).
A flat file database is where all the information is stored in one table. These can be problematic as they:
Increase data redundancy - data is repeated unnecessarily.
Decrease data integrity - data is unreliable as the same data is stored several times increasing the likelihood of errors.
What is a Relational database
A relational database contains more than one table, and the tables are linked through common fields.
Relation database It is the more efficient database type as it reduces (Advantages of relational databases):
Data redundancy is reduced data that is repeated unnecessarily is reduced.
Data integrity is greater - data is more likely to be correct and reliable.
Queries and Reports - can be created using more than one table.
What is a table
A table consists of one or more records
What is a record
A record is a collection of data items, which may be of different data types, all relating to the individual or object that the record describes
What is a field
A field is part of a record designed to hold a single data item, of a specified type
What is a primary key field
A key field uniquely identifies a record
What is the foreign key
When the primary key from one table appears as a field in a second table, it is known as a foreign key of the second table.
What is a composite
A composite key is one that consists of two or more fields.
What is Data Validation
Validation is the automatic checking of data when it is entered into a computer system.
What is a data type
A data type is a formal description of the kind of data being stored or manipulated within a program or system
What is a relationship
The function of a relationship is to link tables.
Advantages of having links between tables:
⦁ Reduces data redundancy – data that is repeated unnecessarily.
⦁ Increases data integrity - data is more likely to be correct or is reliable as the same data is not stored/entered several times decreasing the likelihood of errors.
⦁ Reports/Queries can be created using data from more than one table.
⦁ Referential integrity is enabled – this ensures data is kept consistent in the tables. For example, when data is deleted from one table, the linked data in other table(s) is also deleted.
What is referential integrity
Referential integrity ensures that an entry cannot be made in one table with a foreign key, if the key field does not exist in the linked table.
What are forms
: Forms are used to enter/collect data in a database
What is a lookup list and advantages
a lookup list is a list of data that can be used to provide all values for a data field.
The advantages of lookup lists are:
⦁ Less chance of mistakes being made.
⦁ Increased speed of data entry so you don’t have to type the data in.
⦁ Limits entry options meaning users can only enter valid values.
What is a query in a database
A query is used to retrieve selected information from a database in order to answer a question
What is a parameter query
A parameter query is where the user is prompted to enter search criteria each time the query is activated.
What is a report
A report is the presentation of information from a query or table in a user-friendly way
What is import
Import is the ability to accept a file produced by other software and place it into the database without having to enter the data again
What is export
To export is to create a data file using one piece of software so that it can be read by a different piece of software.
What is a CSV
CSV – Comma Separated Variable/Value
What is a macro
A macro is a small program used to perform repetitive tasks automatically.
What is Mail Merge
Mail merge documents are template documents which are set up to contain merge fields.
What is a template
Template is a predefined spreadsheet/ document/ layout that can be reused/used/edited/added to documents with the same formatting and formulas
Advantages of templates
An advantage is that it can be re-used and edited for different purposes.
What is a wizard program
A wizard is a program (or software) which helps a user complete a task using step by step instructions (using prompts).
There is no generally agreed definition of big data, and it is not just about the size of the data sets. However, it is agreed that big data cannot be analysed by normal means (2018).
There is no generally agreed definition of big data, and it is not just about the size of the data sets. However, it is agreed that big data cannot be analysed by normal means (2018).
Sources of Big Data
Sources of big data include (2018):
⦁ Text, images and videos uploaded to social media sites.
⦁ Medical records.
⦁ Fitness monitors.
⦁ Financial markets - share price data, currencies, etc.
⦁ Web server logs.
⦁ Mobile phone records.
⦁ E-commerce transactions.
⦁ Device logs (Internet of things).
What is Volume
This is large data sets that are so complex that traditional tools, such as relational database management systems, are not able to deal with them effectively. It is the quantity of data produced
What is velocity
Velocity about how fast the data is coming in; the incoming rate of data is very high and therefore the speed of data processing must be high
What is variety
The data that is produced is unstructured and comes in various forms and formats. The challenge is to store the data in a structured format
What is Data Analytics
Data analytics is the application of algorithms to data to identify trends. It can include statistical analysis or Artificial Intelligence. It is analysing data to draw conclusions
