Is couchbase server fast enough

is couchbase server fast enough if we want to query all documents in it…does it take much much time to query billions of documents?? can i see the benchmarks??we quit mysql because we have read in forums that it takes like 12-13 hours to run query on billion of rows … also indexing increases speed but it takes much more space like 20x to remain in hard disk …what should we do for faster speeds?