面试题与答案

Tableau is a data visualization and business intelligence tool that allows users to connect, visualize, and share data in a way that provides insights and facilitates decision-making.

A calculated field is a user-defined field that performs computations on the existing fields in the data source. It allows users to create new data based on the existing data in the dataset.

Example:

Example: Profit Margin = (Profit / Sales) * 100

A worksheet is a single chart or map, while a dashboard is a collection of sheets arranged on a single canvas. Dashboards are used to combine multiple visualizations to tell a more comprehensive story.

Aggregation in Tableau refers to the process of combining data at a higher level to provide a summary. Functions like SUM, AVG, MIN, and MAX are examples of aggregations that can be applied to measures in Tableau.

A dimension is a categorical field that defines the discrete data points, while a measure is a quantitative field that provides the values to be analyzed. Dimensions are typically used on the rows and columns shelf, while measures are used in the data pane for analysis.

A discrete field contains distinct, separate values and is often categorical. A continuous field, on the other hand, represents a range of values and is typically numerical. Discrete fields are used for dimensions, and continuous fields are used for measures.

The Tableau Repository is a directory on the computer where Tableau Desktop is installed. It contains configuration files, logs, and other settings related to Tableau. The default location is 'My Tableau Repository' in the 'Documents' folder.

To create a trend line in Tableau, right-click on a measure in the view, hover over 'Trend Lines,' and choose the appropriate type (linear, logarithmic, etc.). Trend lines help in identifying patterns and trends in data.

A Tableau Workbook (TWB) file is a XML-based file that contains the information necessary to connect to a data source, define calculated fields, and organize the layout of worksheets and dashboards. It does not store the data itself but rather the metadata for the workbook.

To create a parameter in Tableau, right-click on a blank space in the Data pane, select 'Create Parameter,' and define the parameter properties. Parameters allow users to create dynamic and interactive elements in the workbook.

A Live connection directly queries the data source in real-time, while an Extract creates a snapshot of the data that is stored in Tableau's proprietary format (.hyper) for faster performance.

Data can be filtered in Tableau using various techniques such as Quick Filters, Context Filters, and Top N filters. Users can also create calculated fields for more advanced filtering.

Tableau Prep is a data preparation tool that allows users to clean, shape, and combine data for analysis in Tableau. It helps in preparing data by handling tasks like cleaning, splitting, and aggregating data.

To create a dual-axis chart, drag a second measure to the right of the existing axis. Then, right-click on the second axis and select 'Dual Axis.' This allows for the comparison of two measures with different scales on the same chart.

To create a map in Tableau, drag a geographical dimension (like Country or State) to the Rows or Columns shelf. Tableau will automatically recognize the geographical data and generate the map. You can then drag measures to the color or size shelf for further customization.

Data blending in Tableau is the process of combining data from multiple data sources in a single view. It is often used when the data required for analysis comes from different sources, and a relationship between the sources needs to be established.

To create a calculated table, you can use the Data pane. Right-click on a blank space in the Data pane, select 'Create Calculated Table,' and define the calculations and columns you need. This feature allows you to create tables based on calculated expressions.

Tableau Server is a platform that allows organizations to publish, share, and collaborate on Tableau content. It provides a centralized location for storing and managing Tableau workbooks and dashboards, making it easier for users to access and interact with the data.

Data refresh in Tableau Server can be scheduled using the 'Refresh Schedules' option. Admins can set up schedules to refresh extracts at specified intervals, ensuring that the data remains up-to-date for users accessing Tableau Server.

The Pages shelf in Tableau is used for creating animated visualizations over time. It allows users to analyze how data changes over a specified dimension (e.g., time) by creating a series of static visualizations that can be viewed sequentially.