Hi
I need to hold db table in memory due to performance problems (many selects on this table each iteration).
I thought to use hibernate session for this , when the application is up i will load all objects into the session (select * from table) and keep the session open so my data will be updated.In runtime i will use find command.
What do think on this solution ? if i use @version does it qurey the db on every find ? (so my performance will remain poor).

I think you might misunderstand how a session works. Sessions do not automatically update the database you need to actually call update or save on an persistent object for this to happen.

"Select *" is usually slower than declaring each field. You might want to try declaring the fields or annotation.

If your annotations are large then include in the Select only the Annotations you actually need. So that hibernate doesn't load the whole hierarchy.

Use lazy loading properly. Don't lazy load objects you always need. And do lazy load objects that you rarely need.

I am not sure about @Version I haven't used it, but take a look through the hibernate documentation I am sure it's in there somewhere.