Cross-database joins in Tableau - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a cross-database join in Tableau?

A cross-database join in Tableau is when you combine data from two or more different databases or data sources into a single view by joining tables across those sources.

beginner

True or False: Cross-database joins require the data sources to be of the same type (e.g., both SQL Server).

False. Cross-database joins can combine tables from different types of databases, like SQL Server and Excel.

intermediate

What is a key difference between cross-database joins and data blending in Tableau?

Cross-database joins combine data at the row level before aggregation, while data blending combines aggregated data after separate queries.

intermediate

Name one limitation of cross-database joins in Tableau.

One limitation is that performance can be slower because Tableau has to query multiple databases and join data on the fly.

beginner

How do you create a cross-database join in Tableau?

You connect to multiple data sources, drag tables from different sources into the join area, and define join keys just like a normal join.

What does a cross-database join allow you to do in Tableau?

A Join tables from different databases into one view

B Only join tables from the same database

C Create charts without any data source

D Export data to Excel automatically

Cross-database joins let you join tables from different databases or data sources into a single view.

Which of these is a key difference between cross-database joins and data blending?

A Cross-database joins only work with Excel files

B Blending is faster than cross-database joins

C Cross-database joins combine data before aggregation; blending combines after

D Data blending requires no join keys

Cross-database joins combine data at the row level before aggregation, while blending combines aggregated data.

Which is NOT a limitation of cross-database joins?

A Slower performance due to multiple data sources

B Cannot join tables from different databases

C Complexity in managing join keys

D Potential data refresh delays

Cross-database joins specifically allow joining tables from different databases, so A is not a limitation.

To create a cross-database join, you must:

A Connect to multiple data sources and drag tables into the join area

B Only use one data source

C Write SQL code manually

D Export data to CSV first

You create cross-database joins by connecting to multiple sources and dragging tables into the join area.

Cross-database joins in Tableau can combine data from:

A Only one database at a time

B Only cloud databases

C Only local files

D Different types of databases like SQL Server and Excel

Cross-database joins can combine data from different types of databases and file sources.

Explain what a cross-database join is and how it differs from data blending in Tableau.

Think about when the data is joined and how that affects your analysis.

Describe the steps to create a cross-database join in Tableau and mention one limitation you might face.

Focus on the practical steps and a common challenge.