The Plan Hit Ratio alert notifies you when its configured condition is met on SQL Server instances so you can investigate and respond.
Mini DBA describes this alert as: The percentage of queries that reuse execution plans from the plan cache, if dipped below will trigger the alert Mini DBA evaluates this alert once a minute so changes are detected quickly.
This alert gives Mini DBA a focused signal for a condition that can affect SQL Server reliability, performance, or operational visibility. It helps the team move from a general problem report to a specific metric, threshold, and investigation path.
Enable it on any monitored SQL Server instance where this condition would require an administrator to investigate or communicate with the application team. Tune noisy development systems after you have a short baseline.
Threshold meaning: %. Major threshold: 20 %. Minor threshold: 60 %. Comparison direction: under. For an under-threshold alert, increasing a threshold makes that severity fire sooner; decreasing it waits until the value falls further. Set the minor threshold as an early-warning level and the major threshold at the lowest acceptable value for the service.
Open the related Mini DBA page for the instance, compare the current value with the recent baseline, identify whether the change is caused by workload, configuration, host capacity, or maintenance, then record the corrective action in the incident notes.
If the alert creates repeated noise, review whether it is enabled on the correct instances, whether maintenance windows are configured, and whether the minor and major routes match the real business impact. Keep enough history to prove the new setting before changing it broadly.