Queries, in the form of
statements, perform all the lookup operations in the database.
Tuning these statements is a top priority, whether to achieve
sub-second response times for dynamic web pages, or to chop
hours off the time to generate huge overnight reports.
SELECT statements, the tuning
techniques for queries also apply to constructs such as
CREATE TABLE...AS SELECT,
WHERE clauses in
DELETE statements. Those
statements have additional performance considerations because
they combine write operations with the read-oriented query
In MySQL Cluster NDB 7.2 and later, the
NDB storage engine supports a join
pushdown optimization whereby a qualifying join is sent in its
entirety to MySQL Cluster data nodes, where it can be
distributed among them and executed in parallel. For more
information about this optimization, see
Conditions for NDB pushdown joins.