Definition: To "Boil The Ocean" is to try to do too much with the resources you have available. Clearly, it would take a lot of heat over a very wide area to boil an ocean. So when someone says to you, "Don't try to boil the ocean" or "You're trying to boil the ocean" they are telling you you're being overly ambitious. They are saying you don't have enough of something needed to achieve such a large-scale goal. They are suggesting you scale back a little to get better results.
Also Known As: "Bite off more than you can chew" or "get in over your head"
Bob's trying to boil the ocean. He thinks he can identify the top three customer satisfaction complaints for all our products for the past year and have a presentation ready for the Board by morning.
Rahit don't boil the ocean. The scanners do enough of a quality check. You can't pull every fifth unit off the production line for testing and still meet the production quotas.