I come with some problems when using mysql cluster(7.1),
There are two data nodes in mysql cluster;
Table T1 (index a) and table T2 (index b) both have about 180,000 records.
the sql statement "select * from T1 left join T2 on T1.a=T2.b where T2.b is null;"
costs about 10.7s when Executed on single node A(only data node A works)
and costs about 7.2s when Executed on single node B(only data node B works);
but it takes about 38.62s when two data nodes work ;
I wanna know :
a)why the sql statement is executed for such a long time?
b)what's the differences between the situation that the sql statement is executed on single worked data node and two data nodes(in the same group) ?
There are two data nodes in mysql cluster;
Table T1 (index a) and table T2 (index b) both have about 180,000 records.
the sql statement "select * from T1 left join T2 on T1.a=T2.b where T2.b is null;"
costs about 10.7s when Executed on single node A(only data node A works)
and costs about 7.2s when Executed on single node B(only data node B works);
but it takes about 38.62s when two data nodes work ;
I wanna know :
a)why the sql statement is executed for such a long time?
b)what's the differences between the situation that the sql statement is executed on single worked data node and two data nodes(in the same group) ?