WGU D426 Data Management Foundations Terms Study Guide | Database Management Terms & Definitions | 2026/2027 Exam Prep

D426 Database Management Foundations Terms
Study Guide

1.1 Database basics
database application
A database application is software that helps business users interact with database systems.
database administrator
A database administrator is responsible for securing the database system against
unauthorized users. A database administrator enforces procedures for user access and
database system availability.


1.2 Database systems
Authorization
. Many database users should have limited access to specific tables, columns, or rows of a
database. Database systems authorize individual users to access specific data.
Rules
Database systems ensure data is consistent with structural and business rules.
query processor
The query processor interprets queries, creates a plan to modify the database or retrieve
data, and returns query results to the application.
query optimization
The query processor performs query optimization to ensure the most efficient instructions
are executed on the data.
storage manager
The storage manager translates the query processor instructions into low-level file-
system commands that modify or retrieve data.
indexes
The storage manager uses indexes to quickly locate data.
transaction manager
The transaction manager ensures transactions are properly executed.
Metadata
Metadata is data about the database, such as column names and the number of rows in
each table.
relational database
A relational database stores data in tables, columns, and rows, similar to a spreadsheet.
All relational database systems support the SQL query language.
relational databases are good for what?

, Relational systems are ideal for databases that require an accurate record of every
transaction, such as banking, airline reservation systems, and student records.
SQL
SQL stands for Structured Query Language and includes statements
that read and write data, create and delete tables, and administer the database system.
All relational database systems support the SQL query language.
big data
The growth of the internet in the 1990s generated massive volumes of online data, called big
data, often with poorly structured or missing information.
MongoDB: big data, open source, noSQL.
NoSQL
The newer non-relational systems are called NoSQL, for 'not only SQL', and are optimized for
big data.
MongoDB: big data, open source, noSQL


1.3 Query languages
INSERT
INSERT inserts rows into a table.


INSERT INTO table_name (column_name1, column_name2, ...)
VALUES (DEFAULT, 'bob', 30, 150);



SELECT
SELECT retrieves data from a table.


SELECT column1, column2, ...
FROM table_name; -- return all data from those columns.



UPDATE
UPDATE modifies data in a table.


UPDATE table_name
SET column_name = 2
WHERE column_id = 3;



DELETE
DELETE deletes rows from a table.


DELETE FROM table_name; -- all rows deleted!

, DELETE FROM table_name WHERE column_name = 'value'; -- delete row




CREATE TABLE
The SQL CREATE TABLE statement creates a new table by specifying the table and column
names.


CREATE TABLE Customers (
customerId INT NOT NULL UNIQUE,
first_name VARCHAR(255) NOT NULL,
age INT CHECK(age > 18)
driverid INT NOT NULL,
PRIMARY KEY (customerId),
FOREIGN KEY (LOCAL_COLUMN_NAME) REFERENCES TABLE_NAME (COLUMN_NAME),
);




1.4 Database design and programming
database design: analysis
The analysis phase specifies database requirements without regard to a specific database
system.
Requirements are represented as entities, relationships, and attributes.
Sometimes called: Conceptual Design
ER diagrams
Entities, relationships, and attributes are depicted in ER diagrams.




database design: logical design
The logical design phase implements database requirements in a specific database system.

, For relational database systems, logical design converts entities, relationships, and attributes
into tables, keys, and columns.
The logical design, as specified in SQL and depicted in a table diagram, is called a
database schema.




key
A key is a column used to identify individual rows of a table.
Tables, keys, and columns are specified in SQL with CREATE TABLE statements.
database design: physical design
The physical design phase adds indexes and specifies how tables are organized on storage
media.
Physical design affects query processing speed but never affects the query result.
data independence
The principle that physical design never affects query results is called data independence.
Physical design affects query processing speed but never affects the query result.
When database designers modify indexes or row order, applications run faster or slower
but always generate the same results.
application programming interface / API
simplify the use of SQL with a general-purpose language.
An application programming interface, or API, is a library of procedures or
classes that links a host programming language to a database.


1.5 MySQL
MySQL Command-Line Client
The MySQL Command-Line Client is a text interface included in the MySQL Server
download.
The Command-Line Client allows developers to connect to the database server, perform
administrative functions, and execute SQL statements.