If you have the disk space, it’s certainly worth adding say 2G of swap.
The other thing to do is to monitor usage while your large job is running. I would use vmstat 5 5 and perhaps log to a file. You’re hoping not to see large values in si or so columns, and not to see the swpd column get close to the size of your swap.
Perhaps see this post:
(It seems possible that the database system is running out of some resource, but I don’t know anything about that.)