XS Job Schedule run concurrently and update same row in DB

Hi all,

My situation is: I create 2 (maybe more) job schedules with same planned time and they call same service. In this service, I update a row in database.

I use XS Admin Tool to observe job schedules. They run successfully, but take a lot of time (about 10 minutes) to finish these job schedules while in case only one job schedules run, it takes less than 1 second. My expectation is many job schedules run concurrently and finish in short time.

I tried to use connection with $.db.isolation.SERIALIZABLE, READ_COMMITTED, REPEATABLE_READ. But, it not work.

How can I solved this problem?