Re: [rules-users] Is there a faster way of doing this in Drools ?

If the structure of the constraints/filters the user can define remains static, and only the values are changing, then a single rule with parametric joins will be enough. E.g.: Params( $cat : categorySet, $minPrice : minPrice, $maxPrice : maxPrice, .... ) Product( category in $cat, price >= $minPrice && <= $maxPrice, num_ratings ... ) You'd then have to update the "Params" according to what the user e.g. selects from a checkbox. A "null" selection would then be converted e.g. categorySet = all categories, minPrice = -infinity, maxPrice = +infinity etc... If, on the other hand, the user is completely free to create their own rules, this strategy may not be applicable. Wouldn't then the bottleneck be the user writing/picking the rules (seconds) rather than their compilation (a few milliseconds)? If so, you might have "horizontal" scalability issues - allowing more and more users to do this - rather than "vertical" ones - responding faster to a single user. If, instead, the criteria are built automatically by a software agent of some sort, then the direct creation might be taken into consideration. You can skip the parsing step by creating the Abstract Syntax Tree directly - the compiler APIs ("Descrs") have a nice fluent structure. Davide btw, what are your rules supposed to do as a consequence? Do you have chaining? or actions? If all you need is selection and filtering, I wonder if a production rule system is the best option for your application, or at least this sub-module... -- View this message in context: http://drools.46999.n3.nabble.com/Is-there-a-faster-way-of-doing-this-in-... Sent from the Drools: User forum mailing list archive at Nabble.com.