Database Flashcards
What is Relationship Database
It is a database that consists of different tables that are linked together which only portrays the main aspect. such as primary key.
what is a flat file?
a flat file is also a database that consist of different field which are filled with information.it is a single file.
What is primary key?
primary key is given to a information which is unique such as National Insurance Number.
different Entities?
one to one/ one to many and many to many
Foreign key?
creates a join between two tables.
what is normalization?
it is the bets possible design for a relationship database.
different things to consider
- null information(data is consisted thought the database)
2. No data is duplicated
Importance of normalization ?
- No data redundancy=to delete duplicated data
- Maintaining and Modifying database= to keep it easy to handle
- Faster sorting and searching=it will produce smaller tables with fewer fields.
Transaction processing
- capturing data
- selecting and managing
- exchanging data
- ACID
- before data is added it has to captured or inputted.
- the data is selected before it is even added
- this is when the information is exchanged such as electronically = email
- this is a set if properties which are processed to make the transaction reliable.
ACID
- Atomicity= it requires a transaction must be processed in its entity or not at all. it must guarantee in all of it transactions.
- consistency=ensures that no transaction can violate any of the defined validation rule.
- isolation=it ensures that the process leads to the same result even it was processed one after another
- Durability=this is when it ensures that when the transaction has been processed it will remain so.
what is indexing in database?
Indexing is a way to optimize performance of a database by minimizing the number of disk accesses required when a query is processed.
