I am trying to validate the following --
1) when one calls session.load(class,serializable) does hibernate check its cache for the existence of a preparedStatement for the load process or does it create a new sql string for each load ?
2) Is there a way to force Hibernate to create preparedStatements for each <mapping> and cache the preparedStatement -- for each state change -- load,update,delete,create ? --DBA's would love this.
3) does the cache lifecycle exist with-in a session's life cycle or sessionFactries lifecycle ?


I am new to this so please be kind..

Prepared Statement caching is the job of the database pool. Both c3po and dbcp do this. So if you configure your pool accordingly, all executed queries will be prepared statment cached, because Hibernate uses prepared statements everywhere. Hibernate will still cache generated SQL, to avoid SQL generation overhead.

Hibernate has a two-level-cache structure, the Session level cache allways exists, and you may optionally use an additional jvm-level cache (EHCache, SwarmCache ...)

gloeglm: does Hibernate cache a java.sql.PreparedStatement or just the String representation of the PreparedStatement ?

As I said, Hibernate does not cache any PreparedStatements at all, the DB-Pool should cache the PreparedStatements. (Both c3po and dbcp do).

Hibernate does cache the generated SQL strings, to avoid the overhead of repeated SQL generation. Multiple requests to createStatement() with the same SQL string results in the same prepared statement when the pool does prepared statement caching.

So basically when you use a proper pool (not the Hibernate builtin one!), every SQL will be generated only once, and the prepared statement for it will be generated only once, too.

Thank you very much -- I will dig into C3P0 --