I don't think any of us have said that 'from' is not good to use. Only that you should understand how it works; with regards to not being reactive, and that it's a linear iteration.
Mark On 15 Oct 2013, at 04:22, Sonata <plz.write...@gmail.com> wrote: > Hi, I remember seeing some best practice and since then it has been in my > mind that the Drools team actually against the use of CE "from". I do > however find it really useful and use it alot (and in fact everywhere). > Could the Drools team clear this up? > > For example, I found it useful because > 1. When a fact is inserted into the working memory, "from" conditions are > not evaluated. > This is good because the fact may not be ready yet (e.g. need updating to > fill in more stuff to complete it in some rules) and evaluating the fact too > early may cause exceptions. Using "from" does not suffer from this issue. > > 2. Also, this is good because I dont get unnecessary calls to getters of > that newly inserted fact for all the rules in the kbase with the class of > that fact in the LHS because they may not be triggered at the end (e.g. > filtered by agenda-groups, activation-groups). I put auditing codes on my > getters to track usage and profiling, hence each call to getters is quite > expensive for me (elapse time recording, database updating, etc.) > > 3. Once a preceding "from" condition fails, all the subsequent "from" > conditions will not be evaluated. Again, this is good to save unnecessary > member accesses to boost performance. > > I know what I dont get using "from" is same pattern node sharing (i.e. same > condition pattern across rules is evaluated only once when "from" is not > used), but it seems to me that the pros outweigh the cons. > > Thanks the Drools team for clarifying > > > > -- > View this message in context: > http://drools.46999.n3.nabble.com/What-is-the-side-effect-of-using-the-CE-from-tp4026368.html > Sent from the Drools: User forum mailing list archive at Nabble.com. > _______________________________________________ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users