Thank you in advance for your time reading this post first. I have to make my rules work with databases with TB of data, so fact management become a major issue when I design my system. Currently I have several main programs which use both stateful and stateless sessions. I would like to collect some good practices to manage the insertion and disposal of facts so that I can keep my working memory healthy. Below are some of my findings in this forum: 1. Insert only relevant facts into working memory with the use of "data preparation" rule together with Drools pipeline (hibernate, mybatis, etc). An excellent example from manstis in the post http://drools.46999.n3.nabble.com/Applying-rules-on-the-data-in-an-RDBMS-... --------------------- rule "bootstrap" salience -100 when $list : List( ) from placeHolder.namedQuery("Smurfs") then for(ExternalObject o : $list ) { insert( o ); } end -------------------- 2. Use "insertlogical" instead of "insert" when inserting facts in rule 3. Implement "garbage collection" rule to clean up unwanted facts I would like to ask: 1. if there are any other suggestion on optimizing fact management? 2. is there a way for the rule engine to directly operate on data in database (perhaps with some other plugin?) Thanks again! -- View this message in context: http://drools.46999.n3.nabble.com/rule-users-Drools-Fact-Management-with-... Sent from the Drools: User forum mailing list archive at Nabble.com.