cache/src/META-INF/read-only.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings version="2.4"
    xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/orm"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <named-query name="findOrdersByCustomer">
        <query>Select o from Order o where o.customer.id = :customerId</query>
        <hint name="eclipselink.read-only" value="true"/>
    </named-query>
    <entity class="model.Order" read-only="true"/>
    <entity class="model.OrderLine" read-only="true"/>
    <entity class="model.Customer" read-only="true"/>

</entity-mappings>