Enable logging of slow database operations

We consider db operations slower than 10s for now.

Fixes #38863

Signed-off-by: Thomas Darimont <thomas.darimont@googlemail.com>

model/jpa/src/main/resources/default-persistence.xml

@@ -124,6 +124,17 @@
             MSSQL returns the whole result at once.
             See https://docs.oracle.com/en/database/oracle/oracle-database/21/jjdbc/resultset.html -->
             <property name="hibernate.jdbc.fetch_size" value="64" />
+
+            <!-- We consider database statements taking longer than 10s as slow
+            See https://docs.jboss.org/hibernate/orm/6.6/introduction/html_single/Hibernate_Introduction.html#slow-queries
+            Note, that this requires the logger configuration: org.hibernate.SQL_SLOW:info
+            -->
+            <property name="hibernate.log_slow_query" value="10000"/>
+
+            <!-- Prepends the name or query text of the executed statement as comment to make it easier to identify slow queries
+            See https://docs.jboss.org/hibernate/orm/6.6/introduction/html_single/Hibernate_Introduction.html#slow-queries
+            -->
+            <property name="hibernate.use_sql_comments" value="true"/>
         </properties>
     </persistence-unit>
 </persistence>

quarkus/runtime/src/main/resources/application.properties

@@ -30,6 +30,9 @@ quarkus.log.category."io.quarkus.arc.processor.IndexClassLookupUtils".level=off
 quarkus.log.category."io.quarkus.hibernate.orm.deployment.HibernateOrmProcessor".level=warn
 quarkus.log.category."io.quarkus.deployment.steps.ReflectiveHierarchyStep".level=error
 
+# Enable logging for slow queries
+quarkus.log.category."org.hibernate.SQL_SLOW".level=info
+
 quarkus.transaction-manager.enable-recovery=true
 # Set default directory name for the location of the transaction logs
 quarkus.transaction-manager.object-store.directory=${kc.home.dir:default}${file.separator}data${file.separator}transaction-logs