With 50,000 rows plyr should be fine, and I've tested it up to 1,000,000 and it's reasonably. The problem is more that it doesn't scale terribly well in the nu

With 50,000 rows plyr should be fine, and I've tested it up to 1,000,000 and it's reasonably. The problem is more that it doesn't scale terribly well in the number of groups.