JPA EclipseLink ORM.XML Mapping for Index

There may be other, harder ways to do it, but here's the easy way to add an index on a column when using EclipseLink and XML mappings for JPA. Simply add an empty "index" tag inside the "basic" tag for that entity.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<entity-mappings

    xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/orm"

    version="2.4">

...

    <entity name="MonitorEvent" class="com.webaction.runtime.MonitorEvent">

        <attributes>

...

            <basic name="timeStamp">

                <index />

            </basic>

...

        </attributes>

    </entity>

</entity-mappings>

Someone involved with JPA (or EclipseLink) should really consider some proper XML mapping documentation, because it is not at all sufficient.