A cache is a temporary data storage system. Fetching cached data can be much faster than fetching it directly from the underlying data set, and helps reduce the number of queries sent, minimizing costs for paid data access.
Data freshness refers to how up-to-date the data in a report is. Different types of reports have different requirements or expectations for data freshness. If you are measuring ad performance on your site or app, for example, daily updates might be sufficient. Reports based on social media analytics, on the other hand, may want their data updated multiple times in a day.
Report performance is a measure of how quickly the report loads. Fetching data directly from the underlying data set can be slow, which in turn makes your reports sluggish to load and respond to viewer changes, like applying filters and date ranges. In addition, for some data sources, such as BigQuery, fetching data directly can cost you money.
Set data freshness for a data source
You must be an editor of the data source to change this setting.
- Edit the data source. You can do this from within a report, or from the Data Sources home page.
- At the top, click Data freshness.
- Under "Check for fresh data," select a new refresh option, if available.
- Click SET DATA FRESHNESS.
Data refresh rates by connector
Different connectors support different data refresh rates, as follows. Note that Google measurement products, such as Ads, Analytics, Campaign Manager, Search Console, YouTube Analytics, and others, refresh every 12 hours. That rate can't be changed.
| Connector | Freshness options |
|---|---|
|
Google measurement products |
Every 12 hours |
| Google Sheets | Every 15 minutes* Every 4 hours Every 12 hours |
| BigQuery |
Every 1 hour |
| Cloud and SQL connectors | Every 1 hour* Every 4 hours Every 12 hours |
| Community connectors | Varies |
| Other connectors | Varies |
* Default refresh rate
How the cache works
Every component in a Data Studio report gets its data from the cache when possible. When a component in your report requests data, the cache remembers the response returned by the underlying platform. If a person viewing the report requests the exact same data (for example, the same dimensions and metrics with the same filter conditions and date range) as a previously received query, then the new request is served by the cache.
If the request can't be served by the cache, Data Studio requests the data from the underlying data set.
Refresh the cache
As noted above, the cache automatically refreshes at certain intervals. Report editors can also manually refresh the cache (see below).
When the cache refreshes, all the old cached data is discarded. New queries generated by the report go directly to the underlying platform and the responses are added to the cache.
Refresh report data manually
You can refresh the cache at any time by viewing or editing the report and clicking Refresh data 
This refreshes the cache for every data source added to the report.
How to tell if report data is cached
You can see if data is coming from the cache by viewing the report and looking in the bottom left corner. When all the charts on the current page are being served from the cache, you'll see a lightning bolt icon along with the time and date of the last update 
Blending and cached data
For a blended data source, the cache will use the setting that satisfies the desired refresh times for all of the data sources included in the blend.
For example, if you blend a Sheets data source having a refresh time of 15 minutes, with a BigQuery data source having a refresh time of 4 hours, the resulting blended data source will have a refresh time of 15 minutes.