CIS275 - Chapter 2: Relational Databases Flashcards
A _____ is a conceptual framework for database software.
database model
The _____ is not optimized for big data.
relational model
Many non-relational databases have come to market since 2000, optimized for big data and are collectively called _____.
NoSQL databases
NoSQL stands for _____ and encompasses a variety of database models.
‘Not only SQL’


The _____ is a database model based on mathematical principles, with three parts:
A data structure that prescribes how data is organized.
Operations that manipulate data structures.
Rules that govern valid relational data.
relational model
A ___ is a collection of values, or elements, with no inherent order.
set
Sets are denoted with braces. Ex: {apple, banana, lemon} is the set containing three kinds of fruit. Since sets have no order, {apple, banana, lemon} is the same set as {lemon, banana, apple}.
A _____ is a named set of possible database values, such as integers, dictionary words, or logical values TRUE and FALSE.
domain
A _____ is a finite sequence of values, each drawn from a fixed domain.
tuple
Ex: (3, apple, TRUE) is a tuple drawn from domains (Integers, DictionaryWords, LogicalValues).
A _____ is a named set of tuples, all drawn from the same sequence of domains.
relation
Ex: The relation below is named Grocery and contains three tuples.

In the relational model, each tuple position is called an _____ and given a unique name.
attribute
Ex: In the Grocery relation, the first, second, and third positions might be named Quantity, FruitType, and OrganicCertification.
Domain, tuple, relation, and attribute =
Data type, row, table, and column



The relational model stipulates a set of operations on tables, collectively called _____.
relational algebra
Like the relational data structure, relational operations are based on set theory.
combines two tables with identical columns into one table.
Union
removes all rows of one table from another table.
Difference
eliminates one or more columns of a table.
Projection

selects a subset of rows of a table.
Selection

combines two tables with different columns into one table.
Join
lists all possible combinations of rows of two tables.
Product


_____, also known as integrity rules, are logical constraints that ensure data is valid and conforms to business policy.
Relational rules
_____ are relational rules that govern data in every relational database.
Structural rules
The relational model stipulates a number of structural rules, such as:
Unique primary key — all tables should have a column with no repeated values, called the primary key and used to identify individual rows.
Unique column names — different columns of the same table must have different names.
No duplicate rows — no two rows of the same table may be have identical values in all columns.
_____ are relational rules specific to a particular database and application.

Business rules
Example business rules include:
Unique column values — in a particular column, values may not be repeated.
No missing values — in a particular column, all rows must have known values.
Delete cascade — when a row is deleted, automatically delete all related rows.










































































































