Docs: Update troubleshoot-queries.md (#27078)

* Update troubleshoot-queries.md

* Update troubleshoot-queries.md

docs/sources/troubleshooting/troubleshoot-queries.md

@@ -11,7 +11,7 @@ weight = 400
 
 This page provides information to solve common dashboard problems.
 
-### I get different results when I rearrange my functions
+## I get different results when I rearrange my functions
 
 Function order is very important. Just like in math, the order that you place your functions can affect the result.
 
@@ -22,3 +22,10 @@ like a bug or visualization issue in Grafana, it is almost always a problem with
 the data source response. Start by inspecting your panel query and response.
 
 For more information, refer to [Inspect a panel]({{< relref "../panels/inspect-panel.md" >}}).
+
+## My query is slow
+
+How many data points is your query returning? A query that returns lots of data points will be slow. Try this:
+- In **Query options**, limit the **Max data points** returned.
+- In **Query options**, increase the **Min interval** time.
+- In your query, use a `group by` function.