DEFS.4.4.2.Final Quiz - sj50179/IBM-Data-Science-Professional-Certificate GitHub Wiki

Final Quiz

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Question 1

Data types define the type of data that can be stored in which part of a database table?

  • Schemas
  • Index
  • Columns
  • Rows

Correct. Data types define the type of data that is stored in columns.

Question 2

Popularity of cloud databases has more than doubled in the past decade. Which cloud service model is driving this?

  • Software-as-a-Service (SaaS)
  • Commercial databases
  • Infrastructure as a Service (IaaS)
  • Platform as a Service (PaaS)

Correct. Software-as-a-Service model is driving the rise in popularity of cloud databases.

Question 3

The DBMS on the server in a 2-tier environment includes multiple layers. Which layer is also referred to as the persistence layer?

  • Data Access layer
  • Database Engine layer
  • Database Storage layer
  • Transmission layer

Correct. The database storage or persistence layer is where the data is stored, either locally or on network storage.

Question 4

Which NoSQL functionality does PostgreSQL use to store non-hierarchical data?

  • Functions
  • HSTORE
  • Replication
  • JSON

Correct. It uses the functionality of NoSQL HSTORE for non-hierarchical data.

Question 5

How can the Entity Relationship Diagram (ERD) model be used?

  • The ERD model helps you to define entities and their attributes, and map them to tables, and identify the relationships between the tables.
  • The ERD model helps you to define the data in each row of a table.
  • The ERD model helps you to design a database with a single table.
  • The ERD model helps you map data types to existing columns and rows.

Correct. The ERD model helps you to define entities and their attributes, and map them to tables, and identify the relationships between the tables. Rather than being used as a model on its own, the ER Model is used as a tool to design relational databases.

Question 6

Which of the following sources is NOT supported by the Db2 Web Console for loading data?

  • Delimited text files (local computer)
  • Python code
  • S3 object storage (AWS)
  • Cloud Object Storage (IBM)

Correct. The Load Data utility does not load data stored in Python code.

Question 7

When creating a foreign key, how can you define an action to take if a parent table row is updated?

  • Use the ALTER TABLE command
  • Use the CREATE TABLE command
  • Use the ON DELETE CASCADE clause
  • Use the rule clause

Correct. Use the rule clause to define what action to take if a parent table row is updated or deleted.

Question 8

Which of the following is a disadvantage of using Indexes?

  • Uses disk space
  • Enhances SELECT query performance
  • Reduce need to sort data
  • Guarantees uniqueness of rows

Correct. This is like adding an index to books, it adds more pages.

Question 9

Which of the following constraints limits the values accepted by an attribute?

  • Check constraint
  • Domain constraint
  • Unique constraint
  • Null constraints

Correct. This constraint enforces domain integrity by limiting values that are accepted by attributes.

Question 10

What is the difference between system schemas and user schemas?

  • System schemas store configuration information and metadata.
  • System schemas contain partitions and user schemas contain metadata.
  • Neither schema contains database objects.
  • Both schemas contain the same objects.

Correct. System schemas store configuration information and metadata, while user schemas store the actual data.

Question 11

Which MySQL tool can you use to visually design a MySQL database?

  • phpMyAdmin
  • mysqladmin
  • MySQL Workbench
  • mysql

Correct. MySQL Workbench is a visual database design tool that integrates SQL development, administration, and database design, creation, and maintenance.

Question 12

When creating a MySQL database using phpMyAdmin, at which point in the process do you define the length of the data in a column?

  • When you add tables to the database.
  • When you name the new database.
  • When you are shown a summary of the structure of the new table.
  • When you define the columns in the table.

Correct. When you define the columns in a table, you can specify the name, data type, and length (if relevant) for each column.

Question 13

What is the maximum size of a data file you can import with phpMyAdmin?

  • Unlimited
  • 3 megabytes
  • 2 megabytes
  • 1 megabyte

Correct. You can import up to 2 megabytes of data at a time using phpMyAdmin.

Question 14

On which operating systems can you install PostgreSQL?

  • You cannot install PostgreSQL locally, it must be Cloud-based
  • UNIX, UNIX like, or UNIX-based systems
  • macOS only
  • macOS, Microsoft Windows, UNIX

Correct. You can download and install PostgreSQL on your own servers, on a range of operating systems such as macOS, Windows, UNIX and UNIX-based or UNIX like systems.

Question 15

Why would you refresh a materialized view in a PostgreSQL database before you use it?

  • You need to refresh a materialized view so you can edit the data.
  • The materialized view only stores the data in memory, so it needs to be refreshed to reflect current data.
  • The materialized view stores the data, so if you need to use the most current data you should refresh the view first.
  • Refreshing a materialized view increases performance.

Correct. This is one of the key differences between materialized views and regular views. You must refresh it to reflect the most current data.