Databases used by SharePoint have outdated index statistics (SharePoint Server)
APPLIES TO: 
2013 2016 2019 Subscription Edition 
SharePoint in Microsoft 365
Rule Name: Databases used by SharePoint have outdated index statistics.
Summary: Outdated index statistics can decrease query performance and cause SharePoint Server 2016 and SharePoint 2013 to respond slowly.
Cause: Index statistics in SharePoint Server databases are out of date.
Note
This SharePoint Health Analyzer rule is enabled daily by default.
Resolution: Edit the rule definition so that the configuration is automatically repaired.
Verify that the user account that is performing this procedure is a member of the Farm Administrators group.
On the Central Administration Home page, click Monitoring.
On the Monitoring page, in the Health Analyzer section, click Review rule definitions.
On the Health Analyzer Rule Definitions - All Rules page, in the Category: Performance section, click the name of the rule.
In the Health Analyzer Rule Definitions dialog, click Edit Item.
Select the Repair Automatically check box, and then click Save.