query to obtain last time an entity has changed
aryankids Jun 10, 2011 12:12 PMDear Team,
Due to nature of the project I am working on at the moment, our audit tables are huge. Although certain column got indexed properly but still querying the audit tables considered as expensive process and should be avoided if it is possible.
Taking above fact into account I would like to know, when was the last time an entity with a given id has been changed before load that entity using envers . The only efficient way I came across is to join audit table and master revision table as follow : (assume my ent.id = 409 )
select globerevis1_.creation_date from myEntity_AUD ent_a0_, Global_Revision globerevis1_ where
ent_a0_.rev_id=globerevis1_.id and ent_a0_.rev_type<>2 and ent_a0_.id=409 and ent_a0_.revend_date_time is null
The above query returns a date which indicates the last time that specific entity with id=409 has changed. I could use this date to check whether it is appropriate to load the entity or not. So far so good but I could not find a way to access revend_date_time using audit reader. So the following is invalid :
final Date lastModifiedDate = (Date) getAuditReader().createQuery().forRevisionsOfEntity(getType(), true, false)
.addProjection(AuditEntity.revisionProperty("timeStamp").max()).add(AuditEntity.property("revend_timestamp").eq(null)).getSingleResult();
So given the above requirement, is there any way that I could access columns which has been created and used for validity audit strategy using auditReader? Is there any other way to check the time an entity has changed before using envers to load the entire object ?
here is part of envers config file :
<property name="org.hibernate.envers.audit_strategy" value="org.hibernate.envers.strategy.ValidityAuditStrategy"/> | |||
<property name="org.hibernate.envers.audit_strategy_validity_end_rev_field_name" value="REV_ID_END"/> | |||
<property name="org.hibernate.envers.audit_strategy_validity_store_revend_timestamp" value="true"/> | |||
<property name="org.hibernate.envers.audit_strategy_validity_revend_timestamp_field_name" value="REVEND_DATE_TIME"/> |
Any help or suggestion is appreciated in advance.
kind regards