Comments on: Bulk Data Operations With NHibernate’s Stateless Sessions

By: Pijush dutta

Pijush dutta — Wed, 25 May 2011 07:31:00 +0000

Hi,

when i am using the same code for bulk insert it gives me this exception from second record “NHibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session”. Note i have a composite key in my nhibernate mapping. It works fine if i close the session after each transaction. but then it is not bulk update i think. Please suggest a way out.

By: Robert

Robert — Tue, 16 Mar 2010 14:04:02 +0000

Something I noticed when using the stateless session is that dependent objects get not cascade as they do using the “normal” session even though cascade=”all” is set. To overcome this problem you need to loop through the dependent objects yourself, which is not a biggy. Just add the additional loops to your repository.

This is from the documentation:
“A stateless session does not implement a first-level cache nor interact with any second-level cache, nor does it implement transactional write-behind or automatic dirty checking, nor do operations cascade to associated instances. Collections are ignored by a stateless session. Operations performed via a stateless session bypass Hibernate’s event model and interceptors. Stateless sessions are vulnerable to data aliasing effects, due to the lack of a first-level cache.”

By: Davy Brion

Davy Brion — Sat, 15 Nov 2008 12:19:13 +0000

@Andrzej

I use NHibernate 2.0.x but i do use it on SQL Server… The last time i used it on Oracle was about a year ago, with NHibernate 1.2. But i actually think most of the batching functionality of NHibernate simply doesn’t work with Oracle, not sure though…

By: Andrzej

Andrzej — Fri, 14 Nov 2008 16:59:54 +0000

Hi Davy,
I am investigating NH batch operations on Oracle and would like to speed it up compared to ODP.NET, but when I looked at NH 2.0 sources I seems like when stateless session is used, batching has no effect, inserts are still done one by one and in my case it performs just like normal session with no batching.
Which NHibernate version did you use and which database you were working on?
Regards,
Andrzej

By: Reflective Perspective - Chris Alcock » The Morning Brew #213

Reflective Perspective - Chris Alcock » The Morning Brew #213 — Fri, 31 Oct 2008 08:32:57 +0000

[...] Bulk Data Operations With NHibernate’s Stateless Sessions – Davy Brion looks at how Stateless Sessions in NHibernate afford memory use benefits when performing bulk data operations. [...]

By: Bulk Data Operations With NHibernate's Stateless Sessions - NHibernate blog - NHibernate Forge

Thu, 30 Oct 2008 19:32:21 +0000

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