NHibernate Perfomance: Cramer vs Cramer

In this last weeks I saw the birth of a new Sport: Kick NHibernate.

So far I still waiting for a real and serious "test" checking difference in performance between NHibernate and something else using a real world environment instead bulk operations… by the way these players had choose the place and the game and we can play their game in their place.

For real this is a really boring task… especially the first time when I ran tests and wait and wait and wait to see results without touch the original code.

Quick check

After a quick watch to a blog post, comparing NH’s performance with something else, before continue reading the post, I’m going directly to the code. First of all I’m checking the NHibernate configuration and the mappings. If the configuration look like the one I’m using for a NH’s course for beginners, in general, the following step is close the browser and the story end there. This time the story is different only because I’m something tired to hear beginners (at least to hear those saying they know what mean persistent-layer and how a good persistent-layer should work).

The competition

The competition is about progressive bulk operation over this domain (note: the Text property has length="8000")

The “test” is loading data from various XMLs and importing/fetching/updating/deleting data on DB. For each operation the “test” is writing imported/fetched/updated/deleted data to a text file so my target is: have the same output with better performance using NHibernate.

This are results of the first long run :

Total Entities	Store	Read all	Read by ID	Find each by text	Update	Delete
1110	27.69’’	2.12’’	2.41’’	29.7’’	3.81’’	4.06’’
2954	77.05’’	5.11’’	6.51’’	182.87’’	9.05’’	9.48’’
4368	139.02’’	6.49’’	12.9’’	209.84’’	13.38’’	17.96’’
8420	292.39’’	13.4’’	29.97’’	471.34’’	22.81’’	33.16’’

Note: for all tests the time reported include the time to write log files.

I’ll try to avoid comments about others parts of the code by the way I have recreated the same behavior.

After the long run the step was: check the schema. The schema proposed does not match with the schema generated by NHibernate; you know that is one of my bets practice : check your schema with the one defined in the mapping.

To change performances I have applied ORM techniques and NHibernate’s best practices:

• Modified the code to create/drop the schema
• cleaned a little bit more the implementation of NH’s POCO entities.
• changed mappings (the competition is about persistent layers based on Object-Relation-Mapping; know what ORM mean is not an option)
• optimize the code

The results after the cure

Total Entities	Store	Read all	Read by ID	Find each by text	Update	Delete
1110	1.05’’	0.22’’	0.28’’	11.05’’	2.48’’	0.1’’
2954	2.02’’	0.59’’	0.67’’	46.74’’	5.06’’	0.07’’
4368	2.51’’	0.87’’	0.98’’	89.93’’	6.63’’	0.12’’
8420	3.5’’	1.6’’	1.78’’	225.42’’	10.88’’	0.33’’

After the cure using compiled queries

Total Entities	Store	Read all	Read by ID	Find each by text	Update	Delete
1110	0.26’’	0.2’’	0.27’’	7.39’’	1.1’’	0.57’’
2954	0.59’’	0.56’’	0.69’’	22.75’’	2.84’’	0.72’’
4368	0.85’’	0.79’’	0.97’’	37.73’’	4.63’’	1.2’’
8420	1.76’’	1.6’’	1.67’’	96.02’’	8.09’’	1.81’’

There are some details here about how each test is done but I said I would avoid comments about the code… well only a note: the “Find each by text” mean find each entity by a text and even show the count of each collection.

Now try to take each result and compare it with the worst after the cure.

Perhaps you would see the code modified… I’m working as consulter, if you want see the code I will happy to send you the price.

Conclusions

Owed to the fact that the speed of light is greater than the sound speed, some people may seem brilliant before one hears the stupidities they say.

The next time you will see a competitions, before look at results, have a look to the driver.