Warn against the independent observation of each element in a list.

groue · groue · commit c2e6c86934bc · 2025-05-11T13:32:50.000+02:00
diff --git a/GRDB/Documentation.docc/Extension/ValueObservation.md b/GRDB/Documentation.docc/Extension/ValueObservation.md
@@ -263,6 +263,10 @@ You can filter out undesired duplicate notifications with the ``removeDuplicates
 
 When needed, you can help GRDB optimize observations and reduce database contention:
 
+> Important: **Keep your number of observations bounded.**
+>
+> In particular, do not observe independently all elements in a list. Instead, observe the whole list in a single observation.
+
 > Tip: Stop observations when possible.
 >
 > For example, if a `UIViewController` needs to display database values, it can start the observation in `viewWillAppear`, and stop it in `viewWillDisappear`.

Original file line number	Diff line number	Diff line change
@@ -263,6 +263,10 @@ You can filter out undesired duplicate notifications with the ``removeDuplicates
`263`	`263`
`264`	`264`	`When needed, you can help GRDB optimize observations and reduce database contention:`
`265`	`265`
	`266`	`+> Important: Keep your number of observations bounded.`
	`267`	`+>`
	`268`	`+> In particular, do not observe independently all elements in a list. Instead, observe the whole list in a single observation.`
	`269`	`+`
`266`	`270`	`> Tip: Stop observations when possible.`
`267`	`271`	`>`
`268`	`272`	> For example, if a `UIViewController` needs to display database values, it can start the observation in `viewWillAppear`, and stop it in `viewWillDisappear`.