[rules-users] Performance consideration in rule writing

Hi, team, I have some quick questions here regarding performance best practices of rule writing. See below two pieces of rules: Rule "1" Salience 100 No-loop true When $txn : data(sourceid == 5&&txnjustify=="995"&&eval(creditOption($txn)==1)&&eval(isGCSwitch($txn))&&i sCurrencyEquals($txn)==0&&compareToPostThreshold($txn)==2); Then . End Rule "2" Salience 100 No-loop true When $txn : data(sourceid == 5&&txnjustify=="995"&&eval(creditOption($txn)==1)&&eval(isGCSwitch($txn))&&i sCurrencyEquals($txn)==0&&compareToPostThreshold($txn)==1); Then . End Questions: 1. Will I gain better performance if I put the rule differentiator condition "compareToPostThreshold($txn)==2" at the beginning of both rule 1 and 2? 2. I saw salaboy's video claiming that to avoid using eval() in the rule. Do we have any alternative way to do that from a performance consideration or I'd better collect/ prepare all the data before I send them into the session? 3. What's you guys' naming convention for rule's salience? PS: my Drools version is 5.2.0. Best regards Abe