Optimize select new query calls like "select new Holder(entity, entity.something) ..." so the parser does not treat them as shallow ----------------------------------------------------------------------------------------------------------------------------------- Key: HHH-2307 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2307 Project: Hibernate3 Type: New Feature Components: query-hql Versions: 3.2.0.ga Environment: Hibernate Version: 3.2.0ga Database platform: Oracle 9.2, HSQLDB 1.7.3.3, and Derby 10.2.1.6 Reporter: Matt Wheeler Priority: Minor Using the JPA implementation, and the following named query: @NamedQuery(name=Country.COUNTRIES_AS_SELECT_ITEMS, query="select new javax.faces.model.SelectItem(c, c.name) from Country c") Which is called from the following method: public List<SelectItem> getAllCountriesAsSelectItems() { return entityManager.createNamedQuery(Country.COUNTRIES_AS_SELECT_ITEMS).getResultList(); } the following SQL is generated: Hibernate: select country0_.id as col_0_0_, country0_.name as col_1_0_ from Country country0_ Hibernate: select country0_.id as id3_0_, country0_.name as name3_0_ from Country country0_ where country0_.id=? Hibernate: select country0_.id as id3_0_, country0_.name as name3_0_ from Country country0_ where country0_.id=? Hibernate: select country0_.id as id3_0_, country0_.name as name3_0_ from Country country0_ where country0_.id=? Hibernate: select country0_.id as id3_0_, country0_.name as name3_0_ from Country country0_ where country0_.id=? Hibernate: select country0_.id as id3_0_, country0_.name as name3_0_ from Country country0_ where country0_.id=? Assuming that we have 5 countries in the database, calling the method above would result in 6 queries. The first query appears to get all of the ids, and the next 5 queries appear to retrieve the objects by id. However, if we change the query to: "select new javax.faces.model.SelectItem(c.name) from Country c" and only select an attribute of country, instead of an attribute of the country and the country entity as well, it will only issue 1 query I was just wondering if this could be optimized so that there are not n+1 queries in the new Holder(entity, enity.a) instance Just for reference: As per issue HHH-544 Select new n+1 queries, Gavin responded that the parser treats all select new calls as shallow, as is manifest in the above example. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira