In absence of an explanation the manual does acknowledge the limitation as follows
As noted elsewhere in this chapter, MySQL Cluster does not handle large transactions well; it is better to perform a number of small transactions with a few operations each than to attempt a single large transaction containing a great many operations. Among other considerations, large transactions require very large amounts of memory.
http://dev.mysql.com/doc/refman/5.5/en/mysql-cluster-limitations-transactions.html
"As noted elsewhere in this chapter" ... I have looked but yet to find anything specific.
FYI the alternatives are:
- Loop through iterations with a row
LIMIT
(say 10,000) - If inserting into an empty table consider
LOAD DATA
or even using innodb and finallyALTER TABLE ... ENGINE = ndbcluster
(neither are transactional)