java - Selecting multiple data from the database at the same time -

i creating java application needs collect loads of data, process data objects , return objects list.

all of data collected different tables in database (some joined of them different sql calls)

i thinking of getting data through different threads since multiple threads cannot use same connection acess data in database have create new connection each of these threads.

my question is: best way acess , process multiple data database @ same time?

if have enough memory use full second level change syncs database. using cache makes extremely faster. if won't have enough memory on server/client can cache query on sqlserver table has values query , table gets updated every second.

otherwise can use threadpool threads inserts queryresults shared object result.