Wolfgang, Thanks for the reply. The N threads means I need to be able to query/check the list very often. The through put is undetermined, but could be as high as several hundred lookups per second. It seems you agree that using a stateful session would require me to process each request serially, unless I wanted to spin up several copies of my facts. That would seem inefficient. Date: Mon, 18 Apr 2011 10:05:29 +0200 > From: Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; > Subject: Re: [rules-users] Searching a list - Is Drools the answer? > To: Rules Users List <rules-users(a)lists.jboss.org&gt; > > It's possible that putting the "constants" into rules will result in a > rule > building process that's more complex than what you need to do if this data > is in facts. Notice that your Object_1 has to participate in (at least) > three different matching scenarios, which is a simple thing for a fact, > but > may need three rules if FirstName and LastName are literals in rules. > > A (serially) reusable Stateful Session would need to be set up with the > 10k > facts. A search request enters an object, produces results, and retracts > the > request; then the session is ready for the next request. (The N threads > you > are talking about results from some overall application context?) > > Regards > Wolfgang > > 2011/4/18 Drools User <drools2030(a)gmail.com&gt; > > > I have been using Drools for several years, but just with constraints > > (rules) on 1 set of objects at a time. Think many rules, few facts in a > > stateless session. I have been given a new project at the office which > > requires having about 10-100k facts and few rules. These 10k facts would > be > > basically constants, a list of things I need to search on each request. > I > > would then need to load a single object, based on a request to see if my > > request object matched the list. It is somewhat a simple search, but I > need > > to be able to inject aliases and search partial matches in addition to > exact > > matches. A generic example: > > > > List: > > Object 1 (FirstName=John, LastName=Smith) > > Object 2 (FirstName=Will, LastName=Smith) > > Object 3 (FirstName=Jon, LastName=Smith) > > > > Request/Use Case: > > LastName=Smith, would return all 3 objects, but marked as single match > > LastName=Smith, Firstname =John, Would return object 1, as exact double > > match, and Object 3 a nickname double match > > LastName=Smith, Firstname =J, Would return object 1 and 3, as partial > match > > > > In the second request, I need to run all names through a nickname > DB/list > > to explode the name into multiple search patterns. Possibly using ( > > http://code.google.com/p/nickname-and-diminutive-names-lookup/) > > > > Hopefully that explains a bit about the problem. > > > > So to the question, there are a few ways to solve this. The simplest is > > just SQL from a DB, but this proves to be slow to search all the ways I > > need. I need sub second response times. An in memory DB is another > possible > > solution we are looking at. Not to think of Drools as the golden hammer, > but > > this smells like something I can use Drools for. My first thought was to > > load the "List" as facts into a stateful session. My concern is wouldn't > I > > need N copies of the list loaded to have N threads? This would be > > inefficient if so. I know rules aren't copied per working memory, but is > > there a way to create a master working memory for facts to use? > > > > So my second thought is to convert my List into rules so they would only > be > > stored once in the system, regardless of number of threads using the > engine. > > > > What do you guys think, am I on the right track with this? Is Drools a > good > > way to do this or is there something better I have overlooked? > > > > Thank you for taking the time. > > -Drools user >