In DB2, e.g if you issue below sql statement 100 times, insert into TableA (id , fields) values (1, 'val1'); insert into TableA (id , fields) values (2, 'val2'); insert into TableA (id , fields) values (3, 'val3'); ......................... insert into TableA (id , fields) values (100, 'val100'); if you set jdbc batch_size to 50, it could be only issue two sql to db instead as below: insert into TableA (id , fields) values (1, 'val1') , (2, 'val2') ,(3, 'val3') ,(4, 'val4') ,......,(50, 'val50') insert into TableA (id , fields) values (51, 'val51') , (52, 'val52') ,(53, 'val53') ,(54, 'val54'),...... ,(100, 'val100')