# Query caching, data freshness policies and VizQL scaling

*Tableau Consultant Study Guide · Design and Troubleshoot Calculations and Workbooks · Last updated November 3, 2026 · https://www.certifyforce.com/study-guide/tableau-consultant/design-and-troubleshoot-calculations-and-workbooks/query-caching-data-freshness-policies-and-vizql-scaling*

Balance cache reuse against freshness on Tableau Server and Tableau Cloud: the tsm data-access caching values, workbook data freshness policies for live connections, Server and Cloud defaults, VizQL and Cache Server process tuning, parameters that defeat the cache, and the retired View Acceleration feature.

- Certification: Salesforce Tableau Consultant
- Exam section: Design and Troubleshoot Calculations and Workbooks
- Study guide: https://www.certifyforce.com/study-guide/tableau-consultant

**Official exam objective:**

> Maximize caching for Tableau Server.

## What the exam expects

- Choose the tsm data-access caching value that meets a stated freshness tolerance, and know how the change is applied.
- Choose a workbook data freshness policy for a live-connected workbook, and recognize when no policy can be set.
- Contrast the Tableau Server and Tableau Cloud cache defaults and who sets each level.
- Tune VizQL Server, Cache Server and Backgrounder processes for user traffic, one change at a time.
- Spot workbook designs that defeat the cache, and treat View Acceleration as a 2024.2 feature that is now retired.

Key terms:
- **Query cache:** stored results of queries used to fetch data, reused by later visits.
- **Refresh frequency:** the server-wide caching value set with tsm data-access caching set.
- **Data freshness policy:** a workbook-level setting that decides when cached data is too old to show.
- **VizQL Server process:** the process that loads and renders views, usually the first to strain under user traffic.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Server default caching | Cache and reuse data for as long as possible (low) | [Configure Data Cache](https://help.tableau.com/current/server/en-us/config_cache.htm) |
| Numeric -r value | Maximum number of minutes data is cached | [Configure Data Cache](https://help.tableau.com/current/server/en-us/config_cache.htm) |
| always or 0 | Cache refreshed each time a page is reloaded | [Configure Data Cache](https://help.tableau.com/current/server/en-us/config_cache.htm) |
| Applying the change | tsm pending-changes apply, which restarts Tableau Server | [Configure Data Cache](https://help.tableau.com/current/server/en-us/config_cache.htm) |
| Policy prerequisites | Workbook owner; live connection | [Data Freshness Policy](https://help.tableau.com/current/server/en-us/data_freshness_policy.htm) |
| Not available | Tableau Desktop; extract and file-based data sources | [Data Freshness Policy](https://help.tableau.com/current/server/en-us/data_freshness_policy.htm) |
| Tableau Cloud default | Cached data refreshed every 12 hours | [Data Freshness Policy](https://help.tableau.com/current/server/en-us/data_freshness_policy.htm) |
| VizQL tuning | Add one VizQL server process at a time and measure | [Optimize for User Traffic](https://help.tableau.com/current/server/en-us/perf_optimize_user_traffic.htm) |
| Session timeout default | vizqlserver.session.expiry.timeout is 30 minutes | [Optimize for User Traffic](https://help.tableau.com/current/server/en-us/perf_optimize_user_traffic.htm) |
| View Acceleration | Retired: Cloud June 2026, Server 2026.2 | [View Acceleration](https://help.tableau.com/current/server/en-us/data_acceleration.htm) |

## Check yourself

- Why does tsm pending-changes apply need planning after a cache change?
- What units can the Ensure data is fresh every option use?
- When did View Acceleration refuse to accelerate a view because it was already quick?
- Why can a slow view at every hour of the day point away from server tuning?

## Sources

- [Set a Data Freshness Policy for Query Caches](https://help.tableau.com/current/server/en-us/data_freshness_policy.htm)
- [Configure Data Cache](https://help.tableau.com/current/server/en-us/config_cache.htm)
- [Optimize for User Traffic](https://help.tableau.com/current/server/en-us/perf_optimize_user_traffic.htm)
- [Performance Tuning](https://help.tableau.com/current/server/en-us/perf_tuning.htm)
- [View Acceleration](https://help.tableau.com/current/server/en-us/data_acceleration.htm)
- [Create Efficient Calculations](https://help.tableau.com/current/pro/desktop/en-us/perf_efficient_calcs.htm)
- [Test Your Data and Use Extracts](https://help.tableau.com/current/pro/desktop/en-us/perf_extracts.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 6 linked practice questions, and unlimited timed mock exams are included with the Tableau Consultant pack (USD $19): https://www.certifyforce.com/practice-exams