Author: epbernard Date: 2006-11-30 17:12:54 -0500 (Thu, 30 Nov 2006) New Revision: 10903 Modified: branches/Branch_3_2/HibernateExt/metadata/doc/reference/en/modules/entity.xml Log: ANN-430 refine donc on LAZY/EAGER Modified: branches/Branch_3_2/HibernateExt/metadata/doc/reference/en/modules/entity.xml =================================================================== --- branches/Branch_3_2/HibernateExt/metadata/doc/reference/en/modules/entity.xml 2006-11-30 21:54:27 UTC (rev 10902) +++ branches/Branch_3_2/HibernateExt/metadata/doc/reference/en/modules/entity.xml 2006-11-30 22:12:54 UTC (rev 10903) @@ -1700,7 +1700,7 @@ more information on cascading and create/merge semantics.</para> </sect3> - <sect3> + <sect3 id="entity-mapping-association-fetching" revision="1"> <title>Association fetching</title> <para>You have the ability to either eagerly or lazily fetch @@ -1708,11 +1708,20 @@ to <literal>FetchType.LAZY</literal> or <literal>FetchType.EAGER</literal>. <literal>EAGER</literal> will try to use an outer join select to retrieve the associated object, while - <literal>LAZY</literal> is the default and will only trigger a select - when the associated object is accessed for the first time. EJBQL also - has a <literal>fetch</literal> keyword that allows you to override - laziness when doing a particular query. This is very useful to improve - performance and is decided on a use case to use case basis.</para> + <literal>LAZY</literal> will only trigger a select when the associated + object is accessed for the first time. <literal>@OneToMany</literal> + and <literal>@ManyToMany</literal> associations are defaulted to + <literal>LAZY</literal> and <literal>@OneToOne</literal> and + <literal>@ManyToOne</literal> are defaulted to + <literal>EAGER</literal>. For more information about static fetching, + check <xref linkend="entity-hibspec-singleassoc-fetching" />. </para> + + <para>The recommanded approach is to use <literal>LAZY</literal> onn + all static fetching definitions and override this choice dynamically + through JPA-QL. JPA-QL has a <literal>fetch</literal> keyword that + allows you to override laziness when doing a particular query. This is + very useful to improve performance and is decided on a use case to use + case basis.</para> </sect3> </sect2> @@ -2693,7 +2702,8 @@ alter table Child add constraint FK_PARENT foreign key (parent_id) references Parent</programlisting> - <sect3> + <sect3 id="entity-hibspec-singleassoc-fetching" + label="Lazy options and fetching modes"> <title>Lazy options and fetching modes</title> <para>EJB3 comes with the <literal>fetch</literal> option to define @@ -2806,7 +2816,7 @@ </listitem> <listitem> - the where clause, using @Where (applied on the target entity) or @WhereJoinTable (applied on the association table) + the where clause, using @Where (applied on the target entity) or @WhereJoinTable (applied on the association table) </listitem> <listitem>