Hi! I will need to do an application with four hundred tables. Is secure to do it with hibernate? Is it be supported without problems or performance?
Thanks!

Why not? What kind of problems did you expect exactly?

while we're in it. what's the best connection pool? Hibernate connection pool isn't intended for production use....

I was using C3PO but they have some problems like crashing in the mid of transaction.

All I have to do is just uncomment these lines right?

###########################
### C3P0 Connection Pool###
###########################

hibernate.c3p0.max_size 2
hibernate.c3p0.min_size 2
hibernate.c3p0.timeout 5000
hibernate.c3p0.max_statements 100
hibernate.c3p0.idle_test_period 3000
hibernate.c3p0.acquire_increment 2
hibernate.c3p0.validate false

and should I keep these uncommented?

##############################
### Proxool Connection Pool###
##############################


hibernate.proxool.pool_alias pool1

## set the maximum JDBC 2 batch size (a nonzero value enables batching)

hibernate.jdbc.batch_size 0

## set the maximum depth of the outer join fetch tree

hibernate.max_fetch_depth 1

hibernate.cache.provider_class net.sf.hibernate.cache.HashtableCacheProvider

Do these lines have any effect on hibernate's performance?

They sure do, please look them up in the documentation.