Describe pessimistic lock restrictions (#1796)

Co-authored-by: René Jeglinsky <rene.jeglinsky@sap.com>
Co-authored-by: Adrian Görler <adrian.goerler@sap.com>

Author: 3 people

guides/providing-services.md

@@ -746,12 +746,11 @@ Here's an overview table:
 
 [Learn more about using the `Select.lock()` method in the Java runtime.](../java/working-with-cql/query-api#write-lock){.learn-more}
 
-::: warning
-Pessimistic locking is not supported by SQLite. H2 supports exclusive locks only.
-:::
-
-
 
+::: warning Restrictions
+-  Pessimistic locking is supported for domain entities (DB table rows). The locking is not possible for projections and views.
+-  Pessimistic locking is not supported by SQLite. H2 supports exclusive locks only.
+:::
 
 ## Input Validation