Dear all, Hello,Recently I am intersting in query optimize, and have know that most database's query optimizing methods contain two ：1. Rule Base Optimizer; 2.Cost Base Optimizer. I also know that MonetDB has two-level optimizing ,one is relation algebra optimize and the other is MAL optimize when interprets a sql. I understand relation algebra optimize is no relationship with the column-oriented special query optimize.MAL optimizer may be some relationship with the column-oriented special query optimize. So I want to ask :MAL optimize is also contain Rule Base Optimizer and Cost Base Optimizer? which optimizers is the special query optimizer for the column-oriented and not for tuple-oriented database? Best regards!