Which of the following is a NoSQL database?
Correct Answer:
D
This question falls under theData Concepts and Environmentsdomain, focusing on types of databases. The task is to identify a NoSQL database among the options.
✑ PostgreSQL (Option A): PostgreSQL is a relational (SQL) database, not NoSQL.
✑ MySQL (Option B): MySQL is a relational (SQL) database, not NoSQL.
✑ Oracle (Option C): Oracle Database is a relational (SQL) database, not NoSQL.
✑ MongoDB (Option D): MongoDB is a NoSQL database that uses a document- based model, storing data in JSON-like structures, making it the correct choice.
The DA0-002 Data Concepts and Environments domain includes understanding "different types of databases and data repositories," and MongoDB is a well-known NoSQL database.
Reference: CompTIA Data+ DA0-002 Draft Exam Objectives, Domain 1.0 Data Concepts and Environments.
==============
A data analyst needs to remove all duplicate values between two tables, "Employees" and "Managers," using SQL SELECT statements. Which of the following should the analyst use for this task?
Correct Answer:
B
This question pertains to theData Acquisition and Preparationdomain, focusing on combining and deduplicating data using SQL. The task is to remove duplicates between two tables, meaning the analyst needs a unique set of records from both.
✑ SELECT * FROM Employees UNION ALL SELECT * FROM Managers (Option A):
UNION ALL combines all rows from both tables, including duplicates, which doesn??t meet the requirement.
✑ SELECT * FROM Employees UNION SELECT * FROM Managers (Option B):
UNION combines rows from both tables and automatically removes duplicates, providing a unique set of records, which fits the task.
✑ SELECT * FROM Employees JOIN SELECT * FROM Managers (Option C): This
syntax is incorrect; a JOIN requires an ON clause, and it wouldn??t remove duplicates.
✑ SELECT * FROM Employees CROSS JOIN SELECT * FROM Managers (Option
D ): A CROSS JOIN creates a Cartesian product, resulting in all possible combinations, not removing duplicates.
The DA0-002 Data Acquisition and Preparation domain includes "executing data manipulation," and UNION is the correct SQL operation for combining tables while removing duplicates.
Reference: CompTIA Data+ DA0-002 Draft Exam Objectives, Domain 2.0 Data Acquisition and Preparation.
==============
Due to new reporting requirements, a data analyst must add new classification codes to historical data. Which of the following is the best technique for this task?
Correct Answer:
A
This question falls under theData Acquisition and Preparationdomain, focusing on modifying historical data. The task is to add new classification codes to existing data, which involves adding new rows or columns.
✑ Append (Option A): Appending adds new rows to a dataset, which is suitable if the
classification codes are new records (e.g., a new table of codes to combine with historical data). If the codes are a new column, a join or update might be used, but append fits the context of adding new data.
✑ Binning (Option B): Binning groups data into categories, not suitable for adding
classification codes.
✑ Parsing (Option C): Parsing breaks down data (e.g., splitting strings), not relevant for adding codes.
✑ Union (Option D): Union stacks tables with identical structures, but the task involves adding new data (codes) to historical data, not combining identical tables.
The DA0-002 Data Acquisition and Preparation domain includes "executing data manipulation," and appending is a common technique for adding new data to historical
datasets.
Reference: CompTIA Data+ DA0-002 Draft Exam Objectives, Domain 2.0 Data Acquisition and Preparation.
==============
A data analyst receives four files that need to be unified into a single spreadsheet for further analysis. All of the files have the same structure, number of columns, and field names, but each file contains different values. Which of the following methods will help the analyst convert the files into a single spreadsheet?
Correct Answer:
B
This question is part of theData Acquisition and Preparationdomain, which involves combining data from multiple sources. The files have the same structure but different
values, meaning theyneed to be stacked vertically into one dataset.
✑ Merging (Option A): Merging typically involves joining datasets on a common key (e.g., a customer ID), which isn??t indicated here since the files only differ in values, not keys.
✑ Appending (Option B): Appending stacks datasets vertically, combining rows from files with the same structure into a single dataset, which matches the scenario.
✑ Parsing (Option C): Parsing involves breaking down data (e.g., splitting text), not combining files.
✑ Clustering (Option D): Clustering is a machine learning technique for grouping similar data points, not for combining files.
The DA0-002 Data Acquisition and Preparation domain includes "executing data manipulation," such as appending datasets with identical structures.
Reference: CompTIA Data+ DA0-002 Draft Exam Objectives, Domain 2.0 Data Acquisition and Preparation.
==============
A company's analytics manager wants all reports to be delivered once every seven days. Which of the following is the best delivery method?
Correct Answer:
A
This question pertains to theVisualization and Reportingdomain, focusing on report delivery methods. The requirement for delivery every seven days indicates a scheduled, repeating process.
✑ Recurring (Option A): Recurring delivery schedules reports to be generated and
delivered at regular intervals (e.g., weekly), which matches the requirement of every seven days.
✑ Ad hoc (Option B): Ad hoc reports are one-time, on-demand reports, not suitable
for scheduled delivery.
✑ Custom (Option C): Custom isn??t a standard delivery method; it might refer to tailored reports but doesn??t imply scheduling.
✑ Snapshot (Option D): A snapshot captures data at a specific point, not suitable for recurring delivery.
The DA0-002 Visualization and Reporting domain includes "the appropriate visualization in the form of a report" with delivery methods, and recurring delivery is ideal for weekly reports.
Reference: CompTIA Data+ DA0-002 Draft Exam Objectives, Domain 4.0 Visualization and Reporting.
==============