Question

I have a mapped superclass with two already indexed properties. now i want to create a group index over both properties. until now it worked with:

@MappedSuperclass
Class A {
    @Index(name="pa")
    int a;
    @Index(name="pb")
    int b;
}

According to the hibernate documentation i could annotate my new index with @Table (hibernate annotation). but i dont know what to set for the required appliesTo parameter.

has anybody tried this successfully before?

Answer 1

From Hibernate Documentation:

@Table(appliesTo=”tableName”, indexes = { @Index(name=”index1″,
columnNames={“column1”, “column2”} ) } ) creates the defined indexes
on the columns of table tableName. This can be applied on the primary
table or any secondary table.

Update:
For the @MappedSuperclass you could try to use @Tables annotation

@Tables(value={@Table(appliesTo="table1", indexes={@Index(name="index1", columnNames={"column1", "column2"})}),  
               @Table(appliesTo="table2", indexes={@Index(name="index1", columnNames={"column1", "column2"})})})

But that seems rather tedious.
Note that, @Index annotation has columnNames property, which allows you to specify more than one column. However, I’m not sure whether you should duplicate index definition for each field.