Keys and Relationships
A UID attribute made only for the purpose of identification.
What is an Artificial UID
A ________ entity is used to track data changes over time
What is a History Entity
The simplest database model, used commonly but has limitations.
What is a flat-file model?
A single element of a relation.
What is a tuple?
The full name of DDL
What is Data Definition Launguage?
When an entity contains multiple attributes that could uniquely identify an instance, they are called ___________
What is a Candidate UID
A table will contain no repeated groups or redundant data.
What is First Normal Form
n this model, data is organized into a tree-like structure, and many-to-many relationships aren’t supported.
What is a hierarchical model?
This concept states that the data visible to the users of the database must always be consistent.
What is data consistency?
Daily Double:
The full syntax for a create statement with at least 2 constraints and 4 columns.
What is
CREATE table(
id NUMBER(6) PRIMARY KEY,
name VARCHAR2(50),
age NUMBER(3),
address_id NUMBER(8) FOREIGN KEY REFERENCES ADDRESS(id)
);?
(or something like that)
A relationship between an entity and its self.
What is a Recursive Relationship.
If any attributes are not dependent on the entire primary key, they must be moved to a new table with the primary key, also means no transitive dependencies.
What is Third Normal Form
This model does not have structural independence, and relationships in large databases of this model can become very complex.
What is a network model?
The symbol used for this term in relational algebra is “R”
What is a relation schema?
The purpose of DML
What is manipulating data? (or something like that)
The way to determine what candidate UID to use.
What is The Attribute With Most Control
If a table has any multi-value attributes they must be moved to a separate entity.
What is Second Normal Form
This model is easy to make, but easier to create a poorly designed database model.
What is a relational model?
A logical and atomic unit of work which can contain more than one SQL statement.
What is a transaction?
An Update statement that updates all people with the name John to the name joe
What is
UPDATE people
SET name = "joe"
WHERE name = "John";
A barred relationship creates this type of UID.
What is a Composed Attribute UID
One of these is not a goal of normalization
What is Ensure that only permitted individuals have access to all data.
This model was commonly used before the relational model was invented.
What is a network model?
This schema object can speed up access while querying a table.
What is an index?
A statement that queries first and last name as Name, age/2 and only gets rows that have an age higher than 16
What is
SELECT (first_name + "" + last_name) 'Name', age/2
FROM people
WHERE age > 16; ?