Hi,
I want get the sum number of the resultSet before paging,I write the code:

Query query = session.createQuery("from resource i");
int sumSize=query.list().size();
System.out.println("sum size is "+sumSize);
query.setFirstResult(0);
query.setMaxResults(5);
list = query.list();
int pageSize=list.size();
System.out.println("page size is "+pageSize);

hibernate will execute the 'select' SQL 2 times:

Hibernate: select resource0_.RSBIRID as RSBIRID, resource0_.RSBICatId as RSBICatId, resource0_.RSBIISBN as RSBIISBN from Resource resource0_
sum size is 998
Hibernate: select resource0_.RSBIRID as RSBIRID, resource0_.RSBICatId as RSBICatId, resource0_.RSBIISBN as RSBIISBN from Resource resource0_
page size is 5

how can i modify the code and make hibernate execute only one time ?

You have two different queries that you are explicity asking Hibernate to execute. If you want to improve the performance of your first query use a count(*) instead of fetching your entire table into memory.