Hello,
I have a deadlock problem with oracle.
I have two entity beans, lets say "Order" and "OrderPos". There is a bidirectional OneToMany relationship between Order and OrderPos.
@Entity
public class Order{
long id;
Set<OrderPos> positions;
@Id
@GeneratedValue(...)
public long getId(){...}
public void setId(long id){...}
@OneToMany(cascade=CascadeType.ALL, mappedBy="order")
public Set<OrderPos> getPositions(){...}
public void setPositions(Set<OrderPos> positions){...}
}
public class OrderPos{
long id;
Order order;
@Id
@GeneratedValue(...)
public long getId(){...}
public void setId(long id){...}
@ManyToOne
public Order getOrder(){...}
public void setOrder(Order order){...}
}
For these two classes hibernate generated two tables: Order and OrderPos.
For the Order table it generates a primary key constraint as well as an index on the primary key. For OrderPos it generates a primary key constraint, a foreign key constraint for the orderid, and an index on the primary key.
If I try to delete two Orders with all their Positions concurently, I get a deadlock. This is the sql generated by hibernate to do this.
session 1:
delete from OrderPos where order_id = 4711;
session 2:
delete from OrderPos where order_id = 4712;
session 1:
delete from Order where id = 4711;
session 2:
delete from Order where id = 4712;
With this scenario session 1 receives a deadlock.
Investigating this problem I found, that oracle is expecting an index on all foreign keys of a table to prevent this situation.
Is there a way to have hibernate generate these indexes? Or is there another way to accomplish this kind of concurrent deletes?
Please help.
Thanx in advance.
PS: Im using default JBoss 4.0.4 RC1; Oracle 9i
