Update mysql.md

ontop · Apr 5, 2024 · afd6046 · afd6046
1 parent 5473444
commit afd6046
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/guide/databases/mysql.md b/guide/databases/mysql.md
@@ -13,12 +13,17 @@ Through the [MySQL](https://mysql.com) connector, Ontop is able to construct VKG
 The following shows the content of a sample `.properties` file that can be used to connect Ontop to MySQL:
 
 ```bash
-jdbc.url = jdbc:mysql://localhost:3306/defaultdatabase
+jdbc.url = jdbc:mysql://localhost:3306/defaultdatabase?useCursorFetch=true
 jdbc.user = user
 jdbc.password = password
 jdbc.driver = com.mysql.cj.jdbc.Driver
 ```
 
+:::warning
+The parameter `useCursorFetch=true` needs to be added to the JDBC URL for streaming to be enabled. Otherwise, the JDBC driver will block until the full result set is fetched, which may cause out-of-memory exceptions when materializing or running large queries.
+:::
+
+
 ## Nested Type Support
 
 Ontop implements explicit compatibility with the MySQL type `JSON` which can be used with the [flatten lens](/guide/advanced/lenses#flattenlens). However, it cannot infer the type of the flattened result column.