CompTIA Data+ Certification DA0-001 Exam Practice Test

Answer : D

Data integrity is the dimension that measures the consistency and validity of data across different data sources. In this case, the data analyst wants to create one column that contains the customers' birth dates, but the data is stored in different formats and locations in the sample schema. For example, some customers have their birth dates in the customer table, while others have their birth years in the sales table. To compile the data into one column, the data analyst needs to ensure that the data is consistent and valid across the tables. Therefore, data integrity is the best explanation for the reason for compilation. Reference:Data Quality Dimensions - DATAVERSITY,The 6 Data Quality Dimensions with Examples | Collibra

Answer : B

This is because a heat map is a visualization that uses colors to represent different values or intensities of a variable. A heat map can be used to show the most-used/most-clicked portions of a homepage that contains more than 30 links by assigning different colors to each link based on how frequently they are clicked by the users. For example, a link that is clicked very often can be colored red, while a link that is clicked rarely can be colored blue. A heat map can help the analyst to identify which links are more popular or important than others on the homepage. The other visualizations are not as effective as a heat map for this purpose. Here is why:

A scatter plot is a visualization that uses dots or points to represent the relationship between two variables. A scatter plot cannot show the most-used/most-clicked portions of a homepage that contain more than 30 links because it does not have a clear way of mapping each link to a point on the graph.

A pie chart is a visualization that uses slices or sectors to represent the proportion of each category in a whole. A pie chart cannot show the most-used/most-clicked portions of a homepage that contains more than 30 links because it does not have enough space to display all the categories clearly and accurately.

An infographic is a visualization that uses images, icons, charts, and text to convey information or tell a story. An infographic cannot show the most-used/most-clicked portions of a homepage that contain more than 30 links because it does not have a consistent or standardized way of representing each link and its click frequency.

Answer : B

The correct join the analyst should complete is B. LEFT JOIN, four rows.

A LEFT JOIN is a type of SQL join that returns all the rows from the left table, and the matched rows from the right table. If there is no match, the right table will have null values.A LEFT JOIN is useful when we want to preserve the data from the left table, even if there is no corresponding data in the right table1

Using the example tables, a LEFT JOIN query would look like this:

SELECT t1.Name, t1.City, t2.Age FROM Table1 t1 LEFT JOIN Table2 t2 ON t1.Name = t2.Name;

The result of this query would be:

Name City Age Jane Smith Detroit NULL John Smith Dallas 34 Candace Johnson Atlanta 45 Kyle Jacobs Chicago 39

As you can see, the query returns four rows, one for each name in Table1. The name John Smith appears twice in Table2, but only one of them is matched with the name in Table1. The name Jane Smith does not appear in Table2, so the age column has a null value for that row.

Answer : C

The correct answer is C. Indexing documents.

Indexing documents is a query optimization technique that involves creating a data structure that allows faster access to the data in the documents. Indexing documents can reduce the amount of data that needs to be scanned for a particular query, thus improving the performance and efficiency of the query.Indexing documents can also help with searching, sorting, filtering, and aggregating the data in the documents12

Answer : C

Answer : A

Simply put, a z-score (also called a standard score) gives you an idea of how far from the mean a data point is. But more technically it's a measure of how many standard deviations below or above the population mean a raw score is. A z-score can be placed on a normal distribution curve.

Answer : A

A data-mining ETL tool is a software application that performs extract, transform, and load(ETL) operations on data for data mining purposes. Data mining is the process of discovering patterns, trends, and insights from large and complex data sets. ETL tools help to prepare the data for analysis by extracting data from various sources, transforming data into a consistent and suitable format, and loading data into a data warehouse or other destination. SSIS (SQL Server Integration Services) is an example of a data-mining ETL tool that is part of Microsoft SQL Server. SSIS provides graphical tools and wizards for building and debugging ETL packages that can work with various data sources and destinations. Therefore, the correct answer is A. Reference: [Data Mining - SQL Server Integration Services (SSIS) | Microsoft Docs], [What Is Data Mining? | Oracle]