if i'm using 2nd level cache... and i manually insert some data into the db via command line (not using a hibernate session)... will the cache return old data to users?

If you are inserting then no because the data didn't exist before but I assume you are talking about updating data that is cached in a L2 Cache. In that case it depends. Entities are fetched off a L2 Cache only when they are selected with a key. This include all find by primary key methods and/or relations that are fetched with a select. HQL queries or SQL queries do not use a L2 Cache. At the same time, you can set a limit for the amount of time an entity stays in a L2 Cache so that you make sure at least every xx seconds you get fresh data.



Farzad-

okay thanks for the explanation on how the 2nd level cache works!

I have to correct myself when I said HQL queries do not use a L2 Cache. This is true if query caching is disabled.



Farzad-

so if there's a table that is quite large and will be read only, it would make sense for the queries to that table to be cached by doing Query.setCachable(true) before the actual execution of query.iterate()? this will cause it to save the results in memory?

this would be able to speed up performance if users where using the same search string more than once correct?

True. Query results are saved by query parameter's values so there will 1 database hit if the same query is fired multiple times. A query's cache is throw away if one of the participating entities is updated with a hibernate session.




Farzad-

Hi All,

if we are updating some data into a collection, will hibernate reloads the whole collection from the database into the cache?


Thanks
Pawan Chopra.

Hi All,

if we are updating some data into a collection, will hibernate reloads the whole collection from the database into the cache?


Thanks
Pawan Chopra.

I'd say no but be more specific so that I can tell you what happens.


Farzad-