Hi, Edson. Thanks for the explanation. Just wanted to clarify one thing. If I have a set of following Column fact objects and I put then into workspace using the 'identity' mode (below are only field values the facts are initialized with, one per line, each line is a separate Column fact): 1) f1='v1', f2='v1' 2) f1='v1', f2='v11' 3) f1='v1', f2='v2' 4) f1='v2', f2='v2' 5) f1='v11', f2='v2' 6) f1='v11', f2='v22 then the condition Column(f1=='v1') Column(f2=='v2') will select facts exactly 5 facts: 1, 2, 3, 4, 5, but NOT 6, correct? Won't the condition above then be the same as: Column(f1=='v1') or Column(f2=='v2') ? Thanks. Vlad PS: any feedback/hints on some other questions I've sent earlier today would be very much appreciated as well! -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli Sent: 07 February 2007 13:15 To: Rules Users List Subject: Re: [rules-users] [Column(f1=='v1', f2=='v2')] vs [Column(f1=='v1') Column(f2== 'v2')] Vlad, The constructions are semantically different. In 3.0.x as default, JBoss Rules will not allow the same fact to match more than one column. So if you write: Column(f1=='v1') Column(f2=='v2') Your rule will only match if there are 2 different objects that each match one of the constraints. While, if you write: Column(f1=='v1', f2=='v2') It will require a single object that matches both constraints. Also, the optimizations (indexing, hashing, etc) are done on a field constraint basis. So, if you have one rule with : Column(f1=='v1', f2=='ONE_VAL') And another rule with: Column(f1=='v1', f2=='ANOTHER_VAL') The constraint f1=='v1' will be evaluated only once. Although, to help optimization, you must keep the constraints that repeat over multiple patterns as the first constraints for each collumn, in the same order. []s Edson Olenin, Vladimir (MOH) wrote: >Hi, > > > >I wonder what is the difference (performance-wise, etc) between these two >constructs: > > > >Column(f1=='v1', f2=='v2') > > > >And > > > >Column(f1=='v1') > >Column(f2=='v2') > > > >? > > > >Both of them should select the same 'Column' facts (where Column.f1=='v1' > > && >Column.f2='v2'), correct? Is one construct more preferable then another > > one? >Does JBossRules hash only the evaluation result of the 'full column' OR >individual field constraints as well? From what I understand, only the full >'Column' is defined as an (alpha?) node while individual constraints within >the node can not be further optimized, correct? > > > >Meaning, if I have another condition somewhere like this: > > > >Column(f1=='v1', f2=='ANOTHER_VAL') > > > >[f1=='v1'] constraint would have to be reevaluated again, while if I define >constraints through two 'separate' columns and the new constraint as > > > >Column(f1=='v1) > >Column(f2=='ANOTHER_VAL') > > > >only the new constraint would have to be reevaluated. Do I understand it >right? > > > >Thanks! > > > >Vlad > >_______________________________________________ >rules-users mailing list >rules-users(a)lists.jboss.org >https://lists.jboss.org/mailman/listinfo/rules-users > > > > >