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:<br>
<br>List:<br>Object 1 (FirstName=John, LastName=Smith)<br>Object 2 (FirstName=Will, LastName=Smith)<br>Object 3 (FirstName=Jon, LastName=Smith)<br><br>Request/Use Case:<br>LastName=Smith, would return all 3 objects, but marked as single match<br>
LastName=Smith, Firstname =John, Would return object 1, as exact double match, and Object 3 a nickname double match <br>LastName=Smith, Firstname =J, Would return object 1 and 3, as partial match<br><br>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 (<a href="http://code.google.com/p/nickname-and-diminutive-names-lookup/" target="_blank">http://code.google.com/p/nickname-and-diminutive-names-lookup/</a>)<br>
<br>Hopefully that explains a bit about the problem.<br><br>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? <br>
<br>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.<br><br>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?<br>
<br>Thank you for taking the time.<br>-Drools user