Merge pull request #1313 from smallrye/doc/1275

Documentation: insist on merging vs concatenating order semantics
smallrye · Jul 3, 2023 · 43c3b61 · 43c3b61
2 parents 263d101 + 5ed6bfb
commit 43c3b61
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/documentation/docs/tutorials/transforming-items-asynchronously.md b/documentation/docs/tutorials/transforming-items-asynchronously.md
@@ -115,6 +115,11 @@ To implement the scenario from the last section, you will use `onItem().transfor
 {{ insert('java/tutorials/TransformItemsAsyncTest.java', 'merge-concat') }}
 ```
 
+!!! important
+
+    - When merging: items from the source `Multi` _may_ be processed **concurrently** depending on the concurrency level that has been set, if any.
+    - When concatenating: items from the source `Multi` are processed **in order**, waiting for each `Uni` to complete before moving on to the next item. 
+
 ## Multi - Transforming an item into a Multi
 
 `onItem().transformToMultiAndMerge` and `onItem().transformToMultiAndConcatenate` transform incoming items into `Multi` streams.