資料新鮮度功能會將報表產生的查詢和結果暫存於記憶體中。當 Looker Studio 遇到先前曾經執行過的查詢，且資料來源的資料新鮮度門檻仍適用時，Looker Studio 會從記憶體中提供報表所需的資料。從記憶體中提供資料，可加快報表效能，並減少可能的查詢費用或配額命中次數。一旦超過資料來源的最新資料門檻，或是發出先前未儲存的新查詢，Looker Studio 就會從基礎資料集擷取資料。這項程序適用於報表中的所有資料來源。
首次查看這份報表時，Looker Studio 會發出查詢，只擷取顯示表格的必要資料。Looker Studio 會暫時記住該查詢及其結果。下次在資料新鮮度門檻 (12 小時) 內查看預設報表時，Looker Studio 可以使用記憶體中的資料，而不需要從資料來源擷取資料。
範例 2：套用篩選器
如要只查看上季的紅色項目，可以調整日期範圍和篩選控制項。即使資料新鮮度已達門檻，由於這是新的查詢，Looker Studio 仍會前往資料來源擷取資料。接著，Looker Studio 會記住這項新查詢及其結果 (如果可行)。
示例 3：資料更新間隔到期
下次查看報表時，時間已過 12 小時。由於 BigQuery 資料來源的資料更新間隔選項已過期，Looker Studio 會清除該資料來源的記憶體，發出新查詢、記住這些結果，並重設該資料來源的資料更新間隔門檻。
資料更新間隔和資料來源憑證
對於使用檢視者憑證的資料來源，每位報表檢視者都有自己的資料新鮮度設定。舉例來說，如果使用者 A 和 B 都查看以使用檢視者憑證的資料來源為依據的報表，使用者 A 的查詢不會影響使用者 B 的報表資料時效性，反之亦然。
對於使用擁有者憑證的資料來源，報表的所有檢視者都受單一資料新鮮度設定的管制。(在所有情況下，資料來源憑證的擁有者都會視為觀看者)。舉例來說，如果使用者 A 擁有資料來源憑證，而使用者 B 發出查詢，導致 Looker Studio 更新報表中的資料，那麼使用者 A 和報表的所有其他檢視者都會看到更新後的資料。
[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-09-04 (世界標準時間)。"],[],[],null,["# Manage data freshness\n\nMost data source types have a data freshness option (the exception to this is extracted data sources). This option lets you balance your need for up-to-date information against report performance and potential query costs or quotas. Each type of data source has its own default data freshness threshold, but you can adjust this threshold as needed. For example, if you are measuring ad performance on your site or app, you might find that daily data updates are sufficient. Reports that are based on social media analytics, on the other hand, may need their data updated multiple times a day.\n\nSet data freshness for a data source\n------------------------------------\n\nNew data sources that you create have a default refresh rate. To change the default data refresh rate, follow these steps:\n\n1. [Edit the data source](/looker/docs/studio/edit-a-data-source).\n2. In the data source configuration page, click **Data freshness**.\n3. Under **Check for fresh data**, select a new refresh option if one is available.\n4. Click **Set Data Freshness**.\n\nSee data refresh rates by connector\n-----------------------------------\n\nDifferent connectors support different data refresh rates, as shown in the following table. Note that Google marketing and measurement products, such as Google Ads, Google Analytics, Campaign Manager 360, Search Console, YouTube Analytics, and others, refresh every 12 hours. That rate can't be changed.\n\n\\* Default refresh rate\n\u003e **Tip** : Report editors can also [manually refresh the data in a report.](#refresh-report-data-manually).\n\nHow data freshness works\n------------------------\n\nData freshness works by temporarily storing in memory the queries and result generated by your reports. When Looker Studio encounters a query that it has seen before and the data freshness threshold for the data source still applies, Looker Studio serves the data that is needed by your report from its memory. Serving data from memory can both speed up your report performance and reduce possible query costs or quota hits. Once a data source's freshness threshold has been exceeded, or a new, previously unstored query is issued, Looker Studio fetches data from the underlying dataset. This process applies to every data source in your report.\n\u003e **Note** : While the data in your reports will not be older than the specified data freshness setting, there is no guarantee that the data will be served from memory for the entire freshness interval.\n\nHere are some examples of data freshness in action.\n\n### Example 1: View a default report configuration\n\nSay that your report connects to a BigQuery data source with the default data freshness setting of 12 hours. In this example, the default report configuration is as follows:\n\n- A table with some dimensions and metrics (for example, Date sold, Item color, Quantity)\n- A date range control set to the last 7 days\n- A filter control with no filters applied\n\nWhen you view this report for the first time, Looker Studio issues a query to fetch only the data that is needed to display the table. Looker Studio remembers that query and its results temporarily. The next time you view the default report within the data freshness threshold (12 hours), Looker Studio can use the data from its memory instead of fetching it from the data source.\n\n### Example 2: Apply filters\n\nIf you want to see only the red colored items for the previous quarter, you can adjust the date range and filter controls. Even though you're within the data freshness threshold, since this is a new query, Looker Studio goes to the data source to fetch that data. Looker Studio then remembers this new query and its results, if possible.\n\n### Example 3: Data freshness expiration\n\nWhen you next view your report, more than 12 hours have elapsed. Because the data freshness option for the BigQuery data source has expired, Looker Studio clears its memory for that data source, issues new queries, remembers those results, and resets the data freshness threshold for that data source.\n\n### Data freshness and data source credentials\n\nFor data sources that use Viewer's Credentials, each viewer of the report has their own data freshness settings. For example, if users A and B both view a report that is based on a data source that uses Viewer's Credentials, user A's queries don't affect the data freshness of the report for user B, and user B's queries don't affect the data freshness of the report for user A.\n\nFor data sources that use Owner's Credentials, all viewers of the report are governed by a single data freshness setting. (In effect, the owner of the data source credential is considered to be the viewer in all cases.) For example, if user A owns the data source credential and user B issues a query that causes Looker Studio to update the data in the report, then user A and all other viewers of the report will see the refreshed data.\n| **Caution:** BigQuery users should be aware that the usual [query costs](https://cloud.google.com/bigquery/pricing#query-pricing-details) apply whenever Looker Studio queries the underlying project. This includes queries that bypass Looker Studio's memory as well as manual and automatic data refreshes.\n\n### Data freshness and data source type\n\nData freshness works the same way for embedded data sources and reusable data sources. To maximize efficiency in terms of query costs and performance, consider using a reusable data source and Owner's Credentials. This will limit data refreshes to a single data source.\n\nRefresh report data manually\n----------------------------\n\nReport editors can refresh the data in a report at any time by following these steps:\n\n1. View the report.\n2. Click **More options** more_vert.\n3. Click **Refresh data** refresh.\n\nThese steps reset data freshness for every data source that is added to the report.\n\nSee data freshness for a report\n-------------------------------\n\nThe time and date of the last data refresh is displayed in the bottom left corner of the report. If the time shown is earlier than when you last made changes to the current report view, for example, by changing a date range or adding a filter, then all the charts on the page are being served from memory.\n\nData freshness and blends\n-------------------------\n\nFor a blended data source, the data freshness setting will be the minimum refresh time for all the data sources that are included in the blend.\n\nFor example, if you blend a Sheets data source that has a refresh time of 15 minutes with a BigQuery data source that has a refresh time of 4 hours, the resulting blended data source will have a refresh time of 15 minutes.\n\nData freshness and embedded reports\n-----------------------------------\n\nViewers can't manually refresh the data in an embedded report. (The data will refresh automatically when the data freshness threshold expires.)\n\nThe [auto refresh settings](/looker/docs/studio/manage-auto-refresh-for-a-report) on a report don't affect the data freshness of a data source. If a report triggers an auto refresh more frequently than the data source triggers a data refresh, the report returns data from memory.\n\nRelated resources\n-----------------\n\n- [Report settings](/looker/docs/studio/report-settings)\n- [Manage auto refresh for a report](/looker/docs/studio/manage-auto-refresh-for-a-report)"]]
