Databases and Distributed systems Flashcards
Database
A structured collection of organized data
Relational Database
A database structure to recognize relations among stored items of information
What does SQL stand for
Structured Query Language
What is SQL used for
Communicating with databases
Validation
An automatic check to ensure that the data entered is sensible and feasible
Verification
Is performed to ensure that the data entered exactly matches the original source
what are the requirements for a database to be in 1NF
No repeated data
The data is atomic
Each record is unique
Requirements for a database to be in 2NF
Meets the requirements for 1NF
All non-key attributes should depend on all parts of the primary key
Requirements for a database to be in 3NF
Meets the requirements for 2NF
All database columns must depend on the primary key, meaning that any column’s value can be derived from the primary key only
What do data dictionaries aid in
Database design and maintenance
What are data dictionaries
They are a collections of names and definitions.
What do data dictionaries describe
The contents, formats and structure of a database and the relationship between it’s elements
What are the five V’s of big data
Volume
Velocity
Variety
Veracity
Value
What does BIG data refer to
Data sets that are too large or complex for traditional data-processing application software to adequately deal with.
What is data mining
Is where companies attempt to extract valuable information form large data sets, Warehouses
