Not a problem. MapReduce across an entire keyspace is slow.
MapReduce when provided with a few bucket/key pairs is the same as a multi-get + processing. You can combine 2i + MR to get quick processing of data. Although, at that point, you might as well just process your data on the client side. Especially if you're just pulling out a slice of bytes. --- Jeremiah Peschka - Founder, Brent Ozar Unlimited MCITP: SQL Server 2008, MVP Cloudera Certified Developer for Apache Hadoop On Tue, Jul 16, 2013 at 4:13 PM, gbrits <[email protected]> wrote: > Wow, high speed on this list! > > I wanted it for near realtime anyway so Map/reduce is out of the question. > Thought somehow it could be done through Riak Search or directly on > secondary indices instead of map/reduce. > Guess not. Oh well, can't have it all. > > Thanks > > > 2013/7/17 Jeremiah Peschka [via Riak Users] <[hidden > email]<http://user/SendEmail.jtp?type=node&node=4028360&i=0> > > > >> Following up on Alex's comments - >> >> If you know which bytes you need to slice, you can store this in a >> secondary index. You can perform range queries across secondary indices (as >> well as keys). >> >> As long as you're storing your data in a way that allows it to be read by >> either Erlang or JavaScript, you should be able to query over it in >> MapReduce. This is typically regarded as a Bad Idea™ since an MR query will >> need to scan all keys in a bucket (which effectively means scanning the >> entire cluster) and is best done as an infrequent activity to transform >> data. >> >> --- >> Jeremiah Peschka - Founder, Brent Ozar Unlimited >> MCITP: SQL Server 2008, MVP >> Cloudera Certified Developer for Apache Hadoop >> >> >> On Tue, Jul 16, 2013 at 3:45 PM, Alexander Sicular <[hidden >> email]<http://user/SendEmail.jtp?type=node&node=4028359&i=0> >> > wrote: >> >>> I would say no. Riak is generally oblivious as to the content of your >>> data. Any ranges or other method you would use to query needs to be >>> explicitly indexed via riak search or secondary indexes. Once you have >>> found your data you could operate over that data in a map reduce, but I >>> can't speak to "binary safe" blob operations in either erlang or JavaScript >>> although I'm inclined to say yes, you would be able to operate over it in >>> m/r. >>> >>> So searching for keys with certain data in the binblob is probably not >>> gonna happen but once you have a key to feed an m/r you could get a slice >>> of that value. >>> >>> Make sense? >>> -Alexander >>> >>> @siculars >>> http://siculars.posthaven.com >>> >>> Sent from my iRotaryPhone >>> >>> On Jul 16, 2013, at 18:17, gbrits <[hidden >>> email]<http://user/SendEmail.jtp?type=node&node=4028359&i=1>> >>> wrote: >>> >>> > First, hello all! >>> > >>> > Coming from Redis, I love that you can just put any binary blob in >>> Redis >>> > which is just treated as a string. This is possible because Redis >>> strings >>> > are what they call 'binary safe'. This makes it possible to return >>> slices of >>> > string-encoded binary data, which is super useful for >>> bitset-operations, >>> > etc. >>> > >>> > I'm investigating Riak and I like it a lot so far. Riak seems to have >>> range >>> > queries (on values, as it seems I must make that distinction with >>> > column-stores), but I'm not sure if strings in Riak are "Binary safe" >>> in the >>> > above sense. If not, is there another way to store binary data in Riak >>> and >>> > still do range queries over them quickly? >>> > >>> > To be exact: I want to do multi-key lookups in Riak, where each >>> returned >>> > result should be of format: <key,slice(featureX,start,end)> >>> > >>> > Thanks, >>> > Geert-Jan >>> > >>> > >>> > >>> > -- >>> > View this message in context: >>> http://riak-users.197444.n3.nabble.com/Does-Riak-support-Range-Queries-over-binary-safe-strings-tp4028356.html >>> > Sent from the Riak Users mailing list archive at Nabble.com. >>> > >>> > _______________________________________________ >>> > riak-users mailing list >>> > [hidden email] <http://user/SendEmail.jtp?type=node&node=4028359&i=2> >>> >>> > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >>> >>> _______________________________________________ >>> riak-users mailing list >>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4028359&i=3> >>> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >>> >> >> >> _______________________________________________ >> riak-users mailing list >> [hidden email] <http://user/SendEmail.jtp?type=node&node=4028359&i=4> >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >> >> >> ------------------------------ >> If you reply to this email, your message will be added to the >> discussion below: >> >> http://riak-users.197444.n3.nabble.com/Does-Riak-support-Range-Queries-over-binary-safe-strings-tp4028356p4028359.html >> To unsubscribe from Does Riak support Range Queries over binary safe >> strings?, click here. >> NAML<http://riak-users.197444.n3.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> >> > > > ------------------------------ > View this message in context: Re: Does Riak support Range Queries over > binary safe > strings?<http://riak-users.197444.n3.nabble.com/Does-Riak-support-Range-Queries-over-binary-safe-strings-tp4028356p4028360.html> > > Sent from the Riak Users mailing list > archive<http://riak-users.197444.n3.nabble.com/>at Nabble.com. > > _______________________________________________ > riak-users mailing list > [email protected] > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > >
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