HiLo vs Identity?

Question

This is the same question as: http://stackoverflow.com/questions/803872/hilo-or-identity

Let's take the database of this site as an example.

Lets say that the site has the following tables:

• Posts.
• Votes.
• Comments.

What is the best strategy to use for it:

Identity - which is more common.

OR

HiLo - which give best performance.

Edit: if HiLo is the best, how the structure of the DB would be?

Answer 1

Not only HiLo gives better perfomance pretty much always, but it also preserves the Unit of Work by avoiding ALL writes until session flush.

Being "more common" (?) doesn't seem like an objective technical advantage.

I recommend that you read http://fabiomaulo.blogspot.com/2009/02/nh210-generators-behavior-explained.html for a detailed explanation of the downsides of choosing identity.

Answer 2

I have some sample codes on how to use MultipleHiLoPerTableGenerator with Hibernate annotation.

Please refer to the bottom part of this blog:

http://shengchien.blogspot.com/2010/10/hibernate-batch-processing-with-mysql.html