NamedQuery.lockMode - JPA annotation element

Annotation Element
LockModeType lockMode

(Optional) The lock mode type to use in query execution. If a lockMode other than LockModeType.NONE is specified, the query must be executed in a transaction.
Default value:
JPA 2.0

This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
ObjectDB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.