- From: Story Henry <henry.story@bblfish.net>
- Date: Wed, 24 Sep 2008 23:17:03 +0200
- To: Paul Gearon <gearon@ieee.org>
- Cc: semantic-web@w3.org, "public-lod@w3.org" <public-lod@w3.org>
As a matter of interest, would it be possible to develop RDF stores that optimize the layout of the data by analyzing the queries to the database? A bit like a Java Just In Time compiler analyses the usage of the classes in order to decide how to optimize the compilation. Henry On 24 Sep 2008, at 20:30, Paul Gearon wrote: > A related point is that processing RDF to create an object means you > have to move around a lot in the graph. This could mean a lot of > seeking on disk, while an RDBMS will usually find the entire object in > one place on the disk. And seeks kill performance. > > This leads to the operations used to build objects from an RDF store. > A single object often requires the traversal of several statements, > where the object of one statement becomes the subject of the next. > Since the tables are typically represented as > Subject/Predicate/Object, this means that the main table will be > "joined" against itself. Even RDBMSs are notorious for not doing this > efficiently.
Received on Wednesday, 24 September 2008 21:17:49 UTC