Re: BigTable - large rows (more than 256MB)
Having too many vertices with the same label shouldn't be a problem. The two most possible causes are:
1) You have a super node that has too many edges.
2) You have a composite index with very low cardinality. Let's say you have 1 million vertices with the same value that is indexed by a composite index, then the index entry for that value will have 1 million rows.
Let me know if you have any follow-ups.