Rohit Sharma just broke the record for the highest runs in an ODI inning when he hit scored 264 runs against the Sri Lankans. This gave Rohit Sharma several exclusive records, among them being the first batsman to have the ODI double-double (two double centuries in ODIs), the only batsman to score 250+ runs in an ODI inning, most boundaries in an ODI inning (33), and several others.
The graph below shows how the record for most runs in an ODI inning has evolved over the course of past 40+ years. It demonstrates the real high bar that Rohit Sharma has set with regards to this record.
To put his innings of 264 into context, here is an observation: In the 1990s, a first innings score of 250+ was considered a very good target, something which most teams easily defended in that era. In fact 250 was a good first inning score even during the times when there were 60 overs in each innings. So a score of even 200+ by a batsman would have been considered impossible. No more now, in the last 5 years itself this threshold has been breached four times, twice by Rohit himself.
This is one record which is unlikely to be broken anytime soon. It was indeed a very, very special knock by Rohit Sharma.