I have a system where we are batching up Hibernate objects and logging
them to the database asynchronously. We are inserting a continuous
stream of many objects. The resulting rows are only accessed with SQL
on an infrequent basis from other processes.

I noticed our system getting bogged down logging one of these types of
objects with a mapping similar to:



Looking at the Hibernate logs, I see that first see my parent object
Foo inserted, then each Bar object in the child list gets its
properties inserted, then each Bar row is updated with the id of its
parent and position in the list.


I have since discovered that the reason we were getting bogged down
doing these updates was that Postgres 7.4.7 doesn't know that it can
use an int8 index when presented with an int4 literal. My experiments
suggest that this has been fixed in Postgres 8. This will fix the
immediate problem.

Still, I would like to make the Hibernate classes we use in this
fashion to only use INSERT. I have enough problems, the less I can
have the database bogged down doing unnecessary work, the better.

Is there any way to add a child list to the database with no UPDATEs?
It seems like that is just the algorithm you use to persist a graph of
objects, but perhaps there is another way to avoid the UPDATE.

Make it a bi-directional association, and use inverse="true" on your <list> tag (see http://www.hibernate.org/hib_docs/v3/reference/en/html_single/#example-parentchild-bidir)

Hi, this works except for the list index part. Doesn't look like i can do that with an inverse association, unless I let the object know its list position, which is ugly but maybe acceptable in this situation.