# Database tuning, extracts and relationship performance options

*Tableau Consultant Study Guide · Evaluate Current State · Last updated November 3, 2026 · https://www.certifyforce.com/study-guide/tableau-consultant/evaluate-current-state/database-tuning-extracts-and-relationship-performance-options*

Find where an existing data structure loses time and pick the least invasive fix: isolate the network from the database, enable referential integrity and join culling, index and permission the database, extract files and custom SQL, slim extracts, and set relationship Performance Options only when the data's shape is known.

- Certification: Salesforce Tableau Consultant
- Exam section: Evaluate Current State
- Study guide: https://www.certifyforce.com/study-guide/tableau-consultant

**Official exam objective:**

> Evaluate existing data structures for performance risks and enhancement opportunities.

## What the exam expects

- Isolate whether slowness comes from the network or the database before changing the design.
- Recommend database-side fixes: referential integrity for join culling, indexes, temp table permissions and spool space, and a database server instead of Access.
- Recommend extracts for file data and unavoidable custom SQL, and slim an extract with filters and hidden fields.
- Set relationship Performance Options (cardinality, referential integrity) only when the data's shape is known.
- Rewrite cross-table switching calculations to switch between aggregates.

Key terms:
- **Join culling:** querying only the joined tables a view needs.
- **Referential integrity:** every row in one table has a matching row in the other.
- **Cardinality:** how unique the values in the relationship fields are.
- **Extract:** a compressed snapshot of data, loaded into memory as needed.
- **Temp tables:** connection-specific tables Tableau creates in the database to improve performance.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Join culling condition | Occurs only where referential integrity is defined | [Database level](https://help.tableau.com/current/pro/desktop/en-us/perf_data.htm) |
| Assume Referential Integrity | Affects performance only on Tableau's end | [Assume RI for joins](https://help.tableau.com/current/pro/desktop/en-us/joins_assume_refinteg.htm) |
| Access indexing threshold | Tables with more than 200,000 rows | [Database level](https://help.tableau.com/current/pro/desktop/en-us/perf_data.htm) |
| Access storage | Officially 2 GB, poor performance well below it | [Database level](https://help.tableau.com/current/pro/desktop/en-us/perf_data.htm) |
| Native versus ODBC drivers | Native often significantly faster | [Use extracts](https://help.tableau.com/current/pro/desktop/en-us/perf_extracts.htm) |
| Custom SQL | Tableau can't optimize it; extract so it runs once | [Use extracts](https://help.tableau.com/current/pro/desktop/en-us/perf_extracts.htm) |
| Hidden fields | Not included when you create an extract | [Use extracts](https://help.tableau.com/current/pro/desktop/en-us/perf_extracts.htm) |
| Default Performance Options | Many-to-Many; Some Records Match | [Performance Options](https://help.tableau.com/current/pro/desktop/en-us/datasource_relationships_perfoptions.htm) |
| Cardinality One on non-unique values | Duplicate aggregate values | [Performance Options](https://help.tableau.com/current/pro/desktop/en-us/datasource_relationships_perfoptions.htm) |
| Fast data types | Numbers and Booleans; strings and dates are slow | [Optimize Workbook Performance](https://help.tableau.com/current/pro/desktop/en-us/performance_tips.htm) |

## Check yourself

- Why is defining referential integrity in the database better than Tableau's Assume Referential Integrity?
- When does Tableau itself prompt you to extract a text file?
- How does Tableau mark Performance Options it found in the data?
- When are extract filters, aggregation, Top N and sampling unavailable?

## Sources

- [Know Your Data at the Database Level](https://help.tableau.com/current/pro/desktop/en-us/perf_data.htm)
- [Test Your Data and Use Extracts](https://help.tableau.com/current/pro/desktop/en-us/perf_extracts.htm)
- [Optimize Workbook Performance](https://help.tableau.com/current/pro/desktop/en-us/performance_tips.htm)
- [How Analysis Works for Data Sources that Use Relationships](https://help.tableau.com/current/pro/desktop/en-us/datasource_multitable_analysis_overview.htm)
- [Optimize Relationship Queries Using Performance Options](https://help.tableau.com/current/pro/desktop/en-us/datasource_relationships_perfoptions.htm)
- [Assuming Referential Integrity for Joins](https://help.tableau.com/current/pro/desktop/en-us/joins_assume_refinteg.htm)
- [Extract Your Data](https://help.tableau.com/current/pro/desktop/en-us/extracting_data.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 10 linked practice questions, and unlimited timed mock exams are included with the Tableau Consultant pack (USD $19): https://www.certifyforce.com/practice-exams