Re: [rules-users] Re: Drools indexing

My test query is result(Index, PaperName, Author, Year, Month) :- paper(Index, name, PaperName), paper(Index, author, Author), paper(Index, year, Year), paper(Index, month, Month). So drools builds alpha-hashing on the 2nd argument, and name-hashing on the 1st argument. Drools performs much more better than XSB/YAP for this query, and I am trying to figure out what is the reason behind.

Would you share some ideas? Thanks, Senlin On Wed, Oct 15, 2008 at 5:40 PM, Mark Proctor <mproctor(a)codehaus.org&gt; wrote: > Senlin Liang wrote: > > Thanks Mark! > > I got another question: what kind of indexing is used in drools? what > field does it index? > > > It wil index the field used in the constraint > Person( name == "mark" ) > Person( name == $var ) > > Both of those pattners will be indexed no the name field, the first is what > we call alpha node hashing, as it's on a literal and the latter is join node > index on the name field. > > I checked the online manual, it seems that I uses hashing index, but i > am not sure the details. > > The reason that I am asking this question is that: drools runs really > faster for one of my program. In this program, there is information > about DBLP publications: > a(primary key, property, values), where primary key is the primary > key of one publication, property can be one of "author, year, ...", > and value is the value of the property. I run the query by joining the > tables together using the primary key. Drools runs really fast for > this program. > > I am wondering whether there is anything behind to make drools fast. > Senlin > > On Wed, Oct 15, 2008 at 3:41 PM, Mark Proctor <mproctor(a)codehaus.org&gt; wrote: > > > Senlin Liang wrote: > > One more question: does drools index intermediate results (such as the > inserted objects in actions)? > > > Any inserted object used in == constraints is indexed for that constraint. > > Is there any cost-based optimization for queries? > > > no > > Thanks > > On Wed, Oct 15, 2008 at 9:10 AM, Senlin Liang <senlin.liang(a)gmail.com&gt; > wrote: > > > Hi all, > > I got one question: How does drools index the objects in memory? Does > it use hashing index, based on what? Or drools uses adaptive indexing? > > Thanks a lot, > Senlin > > > > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > >