According to the documentation for Open Grid Engine (OGE), you can configure hard and soft limits for the allocated slots.
Further reading shows that tasks can run above the soft limit for a set consecutive amount of time, after which it is treated as a hard limit.
Now, perhaps I've missed a section, but I haven't come across what happens when you hit a hard limit. Does it kill your job? Is the job suspended? What happens to the job, and what are some consequences if my job was writing data to an SQL database?