Pass the Tableau Certified Data Analyst Exam TDA-C01 Questions and answers with ValidTests

The REPLACE function is used to replace all occurrences of a substring within a string with another substring. In this case, it can be used to remove the semicolons from the Name field by replacing them with an empty string. For example, REPLACE (“John;Doe”, “;”, “”) = “JohnDoe”. References: The information is based on the following sources:

String Functions - Tableau

Remove special characters and add a semi colon in a word - Tableau

There are different ways to create a table calculation that shows sales growth over each year, but one possible answer is:

SUM([Sales])

LOOKUP(SUM([Sales]), -1)

PREVIOUS_VALUE(0)

 To calculate the sales growth over each year, you need to compare the current year’s sales with the previous year’s sales and divide the difference by the previous year’s sales. You can use the SUM, LOOKUP, and PREVIOUS_VALUE functions to achieve this. The SUM function returns the total sales for each year. The LOOKUP function returns the value of an expression in a target row, specified as a relative offset from the current row. The PREVIOUS_VALUE function returns the value of the expression in the previous row, or a specified value if there is no previous row. The formula for the table calculation is:

(SUM([Sales]) - LOOKUP(SUM([Sales]), -1)) / PREVIOUS_VALUE(0)

This formula subtracts the sales of the previous year (LOOKUP(SUM([Sales]), -1)) from the sales of the current year (SUM([Sales])) and divides the result by the sales of the previous year. If there is no previous year, the formula uses 0 as the denominator (PREVIOUS_VALUE(0)) to avoid division by zero errors.

References:

Tableau Certified Data Analyst Exam Prep Guide, page 11, section “Creating Calculated Fields”

Tableau Help: SUM Function

Tableau Help: LOOKUP Function

Tableau Help: PREVIOUS_VALUE Function

To schedule a refresh of the data, you need to ensure that Tableau Server or Tableau Online can access the database without prompting for credentials. This can be done by embedding the credentials in the workbook or the published data source. You also need to extract the data from the database and publish it as a separate data source or as part of the workbook. A live connection would not allow you to refresh the data on a schedule, as it would always query the database directly. A hyper file is a format for storing extracted data, but it is not a requirement for scheduling a refresh. References:

Tableau Certified Data Analyst Exam Prep Guide, page 10, section “Publishing and Scheduling Data Refreshes”

Tableau Help: Embedding Database Credentials

Tableau Help: Extract Your Data

In the context of filtering data in Tableau, both string and integer parameters can be used to dynamically filter data. A string parameter can be used to filter text-based values, while an integer parameter is suitable for numerical values. In the provided dataset and result URLs, it appears that a unique identifier or key (which could be a string or integer) is being used to filter specific data entries. References: The information is based on the following sources:

An Introduction to Parameters in Tableau

Create Parameters - Tableau

To combine the tables by using Tableau Prep and include only values from Table1 that do not match any values in Table2, you should use a left only join. A left only join is a type of join that returns only the rows from the primary table (Table1) that have no matching rows in the secondary table (Table2). The field values from Table2 will appear as null values in the combined table. A left only join is also known as an anti-join or an exclusion join. References:

Tableau Certified Data Analyst Exam Prep Guide, page 9, section “Preparing Data”

Tableau Help: Join Your Data

Tableau Help: Left Only Join

The LAST() function in Tableau returns the number of rows from the current row to the last row in the partition. When you compute using 'Order Date', it will change the partitioning of the calculation. If 'Consumer' in '2018' is the last row in its partition when computed by 'Order Date', then LAST() will return 0 for that cell.

The LAST() function in Tableau is a table calculation that returns the number of rows from the current row to the last row in the partition. The value of LAST() is 0 for the last row, increases by 1 for each row above the last row, and can be negative for rows below the current row if there are such rows in the partition.

In the provided visualization, LAST() is set to compute using Table (across). Changing the compute mode to use "Order Date" will adjust the partitioning of the data upon which the LAST() function is calculated. Since "Order Date" is likely to be a unique value per row (assuming each order has a unique date), each row becomes its own partition.

For the Consumer segment of the year 2018, if "Order Date" is unique for each row, then the last row in each partition (in this case, each individual row) will have a LAST() value of 0 because there are no other rows in the partition - it's the last row of its own partition.

Therefore, when you change the compute mode of LAST() to use "Order Date", each cell under the Consumer segment for the year 2018 will have the LAST() value of 0, because each order date creates a partition of one, making every row the last in its partition.