I want to create several Indexes in my DB. Unfortunately we have to change the persistence provider from EclipseLink to Hibernate, but nor the solution with javax.persistence.Index neither the solution with Hibernate works.
This is what the class looks like:
@Entity @Table(name = "my_shop") public class Shop extends BaseEntity { @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Calendar lastUpdate; }
This should be the solution with javax.persistence.*:
import javax.persistence.Index; import javax.persistence.Table; @Table(name = "my_shop", indexes = @Index(columnList = "lastupdate") )
The Hibernate annotations are deprecated, so there must be a reason not to use these annotations:
import org.hibernate.annotations.Index; // deprecated import org.hibernate.annotations.Table; @Table(..., indexes = @Index(columnNames = "lastupdate") )
I use Glassfish 3.1.2.2, PostgreSQL 9.1, JPA 2.1 and hibernate-core 4.3.4.Final. If I look in the database, there are no indexes created on the specific field via psql "\d+".
This what my persistence.xml looks like:
... <property name="hibernate.hbm2ddl.auto" value="create"/> <property name="dialect" value="org.hibernate.dialect.PostgreSQLDialect"/> ...
Only EclipseLink can handle this easily:
import org.eclipse.persistence.annotations.Index; @Entity @Table(name = "my_shop") public class Shop extends BaseEntity { @Index @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Calendar lastUpdate; }
I tested the given solutions with all combinations "lastupdate", "lastUpdate" and additional "name" attributes in @Column and @Index, but nothing seems to work.
Update 1
Indeed this solution works:
@javax.persistence.Table(name = "my_shop") @Table(appliesTo = "my_shop" ,indexes = {@Index(columnNames = "name", name = "name"), @Index(columnNames = "lastupdate", name = "lastupdate")} )
But still org.hibernate.annotations.Index;
is marked as deprecated. So is it good practice to use it or not? If not what's the alternative because apparently javax.persistence.Index
doesn't work.
org.hibernate.annotations.Index;
works with every value: create, update, ... javax.persistence.Index
doesn't matter which value "hibernate.hbm2ddl.auto" has, doesn't work.
Indexing. The short answer is that indexing is automatic: Hibernate Search will transparently index every entity each time it's persisted, updated or removed through Hibernate ORM. Its mission is to keep the index and your database in sync, allowing you to forget about this problem.
As the others already mentioned: Hibernated doesn't decide to use or not use an index. Your database does.
Hibernate Search lets you write your own custom DirectoryProvider . The DirectoryProvider implementation benefits from the same configuration infrastructure available for built-in directory providers. The list of properties matching the current index name is passed to the initialize method.
The @Column annotation is defined as a part of the Java Persistence API specification. It's used mainly in the DDL schema metadata generation. This means that if we let Hibernate generate the database schema automatically, it applies the not null constraint to the particular database column.
I use JPA 2.1 with Hibernate 4.3 and PostgreSQL 9.3. I have no problems with indexes
hibernate-commons-annotations-4.0.4.Final.jar hibernate-core-4.3.1.Final.jar hibernate-jpa-2.1-api-1.0.0.Final.jar jandex-1.1.0.Final.jar javassist-3.18.1-GA.jar jboss-transaction-api_1.2_spec-1.0.0.Final.jar
Though my config has
<property name="hibernate.hbm2ddl.auto" value="update"/>
And that's my entity mapping
import javax.persistence.Entity; import javax.persistence.Index; import javax.persistence.Table; @Entity @Table(name = "users", indexes = { @Index(columnList = "id", name = "user_id_hidx"), @Index(columnList = "current_city", name = "cbplayer_current_city_hidx") })
PS. In fact, I have some problems with that annotations. I cannot specify tablespace for index and must create indecies for subclasses in parent class for SINGLE_TABLE hierarchy.
With Hibernate
you need to enter the name
attribute in the @Index
annotation.
import java.io.Serializable; import javax.persistence.Entity; import javax.persistence.Index; import javax.persistence.Table; @Entity @Table( indexes = { @Index(columnList = "description", name = "product_description") }) public class Product implements Serializable { // ... private String description; // getters and setters }
With EclipseLink
is not required, it creates the name
automatically.
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