Consider a query that uses secondary indices. Does this cause the node that received the query to send out a request to all other nodes? That is, does the use of secondary indices require communicating with all other nodes to find data that matches the index lookup?
Best How To :
The best source for information on how querying of secondary indexes works can be found here:
I believe that the portion of the explanation that is relevant to your question is:
"When issuing a query, the system must read from a “covering” set of partitions and then merge the results. The system looks at how many replicas of data are stored—the N value or n_val—and determines the minimum number of partitions that it must examine (1 / n_val) to retrieve a full set of results, also taking into account any offline nodes."
Also note that: "For all 2i queries, the R parameter is set to 1," - http://docs.basho.com/riak/latest/dev/using/2i/#Querying