My Google-fu is weak and I cannot find the answer to the below questions.
$ cat /opt/couchbase/VERSION.txt 2.1.0-718-rel $ cat /opt/couchbase/lib/libv8.ver 447decb75060a106131ab4de934bcc374648e7f2
Then you can get information about this version on github page for this commit:
In this particular case couchbase uses libv8 3.9.7. At this moment debian unstable has 18.104.22.168-4. Most recent release 3.21.6 (9 hours ago).
The answer regarding built-ins:
All of them described in the docs: http://couchbase.com/docs/couchbase-manual-2.0/couchbase-views-writing-u...
Also for reduce you can use special macros instead of reduce function body, which will allow to execute native implementation: http://couchbase.com/docs/couchbase-devguide-2.0/using-built-in-reduces....