D426 Data Management Foundations Exam Questions with Verified Correct Answers

D426 Data Management Foundations Exam

Questions with Verified Correct Answers

DB Administrator

is responsible for securing the database system against unauthorized users.
A _________ ___________ enforces procedures for user access and database system
availability.

DB Designer

determines the format of each data element and the overall database structure

_________ ___________ must balance several priorities, including storage, response time, and
support for rules that govern the data.

DB Programmer

Develops programs or applications that will use the database.

_________ ___________ write applications that combine database query languages and
general-purpose programming languages

DB Users

Consumers of the data no the Database. Can access the DB through the app or query the
database directly.

Transactions

A ___________ is a group of queries that must be either completed or rejected as a whole.

- Ensures transaction are process completely or not at all
- Prevents conflict between concurrent transactions
- Ensure transactions results are not lost

Query Processor

interprets queries, creates a plan to modify the database or retrieve data, and returns query
results to the application.

,- two main functions: manages connections and compiles queries
- Has a Cache Manager that stores reusable information into main memory

Storage Manager

- Translates the query processor instructions into low-level file-system commands that modify or
retrieve data.
- All access to the database data must go through the _______ ________
- Query optimization ensures the most efficient instructions are sent to the _______ ________,
but the _______ ________ can retrieve the data with efficient or inefficient instructions

Transaction Manager

ensures transactions are properly executed. The transaction manager prevents conflicts
between concurrent transactions. The transaction manager also restores the database to a
consistent state in the event of a transaction or system failure.

Log

A file containing a complete record of all inserts, updates, and deletes.

Relational Database

A database that represents data as a collection of tables in which all data relationships are
represented by common values in related tables

Structured Query Language (SQL)

A language used to create and manipulate databases.

Data Types

Format of data in a field, such as text, number, or date.
- Some data types are followed by 2 numbers and set of ().
- Example VARCHAR(10)
- DECIMAL(10,3) - 10 digits and 3 after the decimal

Database Analysis

- Specifies the database requirements
- Requirements are represented by entities, relationships, and attributes

Logical Design

- Database requirements in a specific database system
- Converts entities, relationships into tables, keys, columns

, Physical Design

- Adds indexes and specifies how tables are organized on storage media
- Logical design affects the results
- Physical design affects the performance

MySQL

- Command Line Client is a text interface that's included in MySQL Download
- MySQL Server returns an Error Code and Description when an SQL statement is syntactically
incorrect

Relational Data Structure

A logical data structure in which all data elements within the database are viewed as being
stored in the form of simple tables. DBMS packages based on the relational model can link data
elements from various tables as long as the tables share common data elements.

SELECT

- Relational Operation
- Selects an subset of rows

PROJECT

- Relational Operation
- Eliminates one or more columns in a Table

JOIN

- Relational Operation
- Combines 2 tables by comparing columns

UNION

- Relational Operation
- Selects all rows
- You must have the same amount of columns in both select queries
- The results will get merged into the same columns despite the data types

SELECT first_name, last_name FROM customer
____________
SELECT address, district FROM address;

INTERSECT