Optimize settings for Hibernate ORM

* Optimize settings for Hibernate ORM
* Teach exception handler about the new BatchUpdateException exceptions

Closes #26162

Signed-off-by: Sebastian Hoeninger <Sebastian.Hoeninger@bosch.io>
Signed-off-by: Alexander Schwartz <aschwart@redhat.com>
Co-authored-by: Sebastian Hoeninger <Sebastian.Hoeninger@bosch.io>
Co-authored-by: Alexander Schwartz <aschwart@redhat.com>

model/jpa/src/main/java/org/keycloak/connections/jpa/PersistenceExceptionConverter.java

@@ -32,6 +32,7 @@ import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
+import java.sql.SQLException;
 import java.sql.SQLIntegrityConstraintViolationException;
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
@@ -89,8 +90,12 @@ public class PersistenceExceptionConverter implements InvocationHandler {
 
         Predicate<Throwable> throwModelDuplicateEx = throwable ->
                 throwable instanceof EntityExistsException
-                        || throwable instanceof ConstraintViolationException
+                || throwable instanceof ConstraintViolationException
-                        || throwable instanceof SQLIntegrityConstraintViolationException;
+                // SQL state class 23 captures errors like 23505 = UNIQUE VIOLATION et al.
+                // This captures, for example, a BatchUpdateException which is not mapped to the other exception types
+                // https://en.wikipedia.org/wiki/SQLSTATE
+                || (throwable instanceof SQLException bue && bue.getSQLState().startsWith("23"))
+                || throwable instanceof SQLIntegrityConstraintViolationException;
 
         throwModelDuplicateEx = throwModelDuplicateEx.or(checkDuplicationMessage);
 

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

@@ -92,6 +92,34 @@
 
         <properties>
             <property name="jboss.as.jpa.managed" value="false"/>
+
+            <!-- Execute multiple insert and update statements in a single call to improve bulk insert / update performance.
+            See https://docs.jboss.org/hibernate/orm/6.2/userguide/html_single/Hibernate_User_Guide.html#best-practices-jdbc-batching
+            and https://docs.jboss.org/hibernate/orm/6.2/userguide/html_single/Hibernate_User_Guide.html#batch-session-batch:
+            recommendation between 10 and 50 -->
+            <property name="hibernate.jdbc.batch_size" value="32" />
+
+            <!-- (optional) Allows for more batching for nested objects and less deadlocks, but according to
+            https://docs.jboss.org/hibernate/orm/6.2/userguide/html_single/Hibernate_User_Guide.html#batch-jdbcbatch
+            may also hava a negative impact on performance.
+            See also https://docs.jboss.org/hibernate/orm/6.2/userguide/html_single/Hibernate_User_Guide.html#best-practices-jdbc-batching.
+            Keycloak uses many nested objects spread across multiple tables, so a benefit is likely.
+            -->
+            <property name="hibernate.order_inserts" value="true" />
+            <property name="hibernate.order_updates" value="true" />
+
+            <!-- Batch fetching collections of entity proxies, default 1. Eases N+1 issues to some extent.
+            See https://docs.jboss.org/hibernate/orm/6.2/userguide/html_single/Hibernate_User_Guide.html#fetching-batch -->
+            <property name="hibernate.default_batch_fetch_size" value="8" />
+
+            <!-- Improve cache hits for execution plans.
+            See https://docs.jboss.org/hibernate/orm/6.1/userguide/html_single/Hibernate_User_Guide.html#configurations-query -->
+            <property name="hibernate.query.in_clause_parameter_padding" value="true"/>
+
+            <!-- Increase number of elements fetched at once from Oracle database query result up from 10.
+            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" />
         </properties>
     </persistence-unit>
 </persistence>