hi, this sounds very interesting to me, i'm currently fiddling around with a suitable row and column setup for triples.
i'm about to implement openrdf's sail api for hbase (i just did a lucene quad store implementation which is superfast a scales to a couple of hundreds of millions of triples (http://turnguard.com/tuqs)) but i'm in my first days of hbase encounters, so my experience in row column design is manageable. from my point of view the problem is to really efficiantly store besides the triples themselves the contexts (named graphs) and languages of literal. by the way : i just did a small tablemanager (in beta) that lets you create htables -> from <- rdf (see http://sourceforge.net/projects/hbasetablemgr/) i'd be really happy to contribute on the rdf and sparql side, but certainly could need some help on the hbase table design side. wkr www.turnguard.com/turnguard ----- Original Message ----- From: "Raffi Basmajian" <[email protected]> To: [email protected], [email protected] Sent: Thursday, April 1, 2010 9:45:59 PM Subject: RE: Using SPARQL against HBase This is an interesting article from a few guys over at BBN/Raytheon. By storing triples in flat files theu used a custom algorithm, detailed in the article, to iterate the WHERE clause from a SPARQL query and reduce the map into the desired result. This is very similar to what I need to do; the only difference being that our data is stored in Hbase tables, not as triples in flat files. -----Original Message----- From: Amandeep Khurana [mailto:[email protected]] Sent: Wednesday, March 31, 2010 3:30 PM To: [email protected]; [email protected] Subject: Re: Using SPARQL against HBase Why do you need to build an in-memory graph which you would want to read/write to? You could store the graph in HBase directly. As pointed out, HBase might not be the best suited for SPARQL queries, but its not impossible to do. Using the triples, you can form a graph that can be represented in HBase as an adjacency list. I've stored graphs with 16-17M nodes which was data equivalent to about 600M triples. And this was on a small cluster and could certainly scale way more than 16M graph nodes. In case you are interested in working on SPARQL over HBase, we could collaborate on it... -ak Amandeep Khurana Computer Science Graduate Student University of California, Santa Cruz On Wed, Mar 31, 2010 at 11:56 AM, Andrew Purtell <[email protected]>wrote: > Hi Raffi, > > To read up on fundamentals I suggest Google's BigTable paper: > http://labs.google.com/papers/bigtable.html > > Detail on how HBase implements the BigTable architecture within the > Hadoop ecosystem can be found here: > > http://wiki.apache.org/hadoop/Hbase/HbaseArchitecture > http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html > > http://www.larsgeorge.com/2010/01/hbase-architecture-101-write-ahead-l > og.html > > Hope that helps, > > - Andy > > > From: Basmajian, Raffi <[email protected]> > > Subject: RE: Using SPARQL against HBase > > To: [email protected], [email protected] > > Date: Wednesday, March 31, 2010, 11:42 AM If Hbase can't respond to > > SPARQL-like queries, then what type of query language can it respond > > to? In a traditional RDBMS database one would use SQL; so what is > > the counterpart query language with Hbase? > > > > > ------------------------------------------------------------------------------ This e-mail transmission may contain information that is proprietary, privileged and/or confidential and is intended exclusively for the person(s) to whom it is addressed. Any use, copying, retention or disclosure by any person other than the intended recipient or the intended recipient's designees is strictly prohibited. If you are not the intended recipient or their designee, please notify the sender immediately by return e-mail and delete all copies. OppenheimerFunds may, at its sole discretion, monitor, review, retain and/or disclose the content of all email communications. ============================================================================== -- punkt. netServices ______________________________ Jürgen Jakobitsch Codeography Lerchenfelder Gürtel 43 Top 5/2 A - 1160 Wien Tel.: 01 / 897 41 22 - 29 Fax: 01 / 897 41 22 - 22 netServices http://www.punkt.at
