Hello Aris, On Mon, 2012-05-07 at 09:21 +0700, Aris Setyawan wrote: > Hi, > > In the documentation, it is said that we can have multiple accumulator: > > "The acc_procedure must have at least one inout parameter, one or more > parameters of any sort and must return nothing. It should get the > previously calculated value of the "accumulator" from its first > parameter, calculate a new value and set the result back to the first > parameter." > > How I can declare two accumulator?
In initialization, set the accumulator to a vector of two values. There's no way of passing two individual values but the single value can be some vector, dictionary or class. > > And it is said that: > "The optional merge_procedure must have two inout parameters that > accept values of two "accumulators"... " > > Is there any example that describe the usage of merge_procedure? > I think I just need more advance example. You never need it for procedures that run on Virtuoso Open Source, so don't worry. The merge is useful only in some very special cases with Virtuoso Cluster Edition, when each individual box of the cluster calculate portion of an aggregate for locally stored data and finally partial results are merged together, pairwise, championship style. Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com
