Connecting to and Preparing Data23% of the exam
Live connections and extracts
How a live connection queries the source while an extract is a saved .hyper copy, when each fits, how to build an extract in the Extract Data dialog, and which settings (filters, hidden fields, Number of Rows, incremental refresh, storage) shape it.
Create live connections and extracts: Create a live connection to a data source; Explain the differences between using live connections versus extracts; Create an extract; Save metadata properties in a .TDS; Create a data source that uses multiple connections.
~8 min read · 6 practice questions ·
What the exam expects
- Connect Tableau Desktop to a file or database from the Connect pane and recognize that a live connection queries the source directly.
- Choose between a live connection and an extract given a requirement: up-to-the-minute data versus speed, reduced database load or offline work.
- Create an extract from the Data Source page and the Extract Data dialog, and know that the workbook must be saved to keep using it.
- Shrink an extract with extract filters, hidden fields, aggregation and Number of Rows, and know what incremental refresh requires.
- Key terms: live connection (Tableau sends queries to the source and updates the view from the results); extract (a subset of the data saved separately from the original, in the .hyper format); full refresh (replaces all rows in the extract); incremental refresh (adds only rows that are new since the last extract); extract filter (limits which rows are extracted).
Key facts
Connection types
- Detail
- Live Connection, Extract, Published Data Source; icon next to the data source shows which
Live connection
- Detail
- Sends queries to the database; Data > Refresh shows saved source changes
Extract
- Detail
- Subset saved separately from the source, in .hyper format
Extract benefits
- Detail
- Large data, performance, extra functionality, offline access in Desktop
What starts extract creation
- Detail
- Selecting a sheet tab after Save Settings
Keeping the extract
- Detail
- Connection to the extract is saved only when the workbook is saved
Default refresh
- Detail
- Full refresh replaces all rows
Incremental refresh needs
- Detail
- All rows; not with Aggregation; not on a sample
Hidden fields
- Detail
- Excluded from the extract; Hide All Unused Fields removes them
Physical Tables storage
- Detail
- Filters, aggregation, Top N and sampling disabled
Default data storage
- Detail
- Logical Tables
- What two choices does Data > (data source) > Extract > Remove give you?
- When is Physical Tables the wrong storage option for an extract?
- Why can an incremental refresh on a high-precision timestamp column produce duplicate rows?
- What happens if you choose Deactivate in the Extract Not Found dialog?
- Where does the extract go when you create it from a packaged .twbx workbook?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
Keep reading with the Tableau Desktop Foundations pack
- Core concepts
- Exam traps
- Worked scenario
The pack includes:
- All 26 lessons of the Tableau Desktop Foundations guide, with reading progress
- Interactive decision walks and step-by-step sequence steppers
- Practice exams purchase adds inline bank questions and topic practice (6 questions for this lesson)
- An official source cited for every claim
- An AI tutor that answers from the guide
- Choose guide-only, practice-only, or save $4 with both