Any updates? Actually I am trying to achieve REPLACE/UPDATE ON DUPLICATE KEY CLAUSE  (before insert) using triggers. However I need to know Monetdb's trigger paradigm for the same.  And the docs don't say anything different from the widely known mysql/oracle triggers. Although the db is behaving differently. Please help. Thanks and Regards, Tapomay. ________________________________ From: Tapomay Dey To: Communication channel for Monet DB users Sent: Tuesday, July 31, 2012 8:19 PM Subject: Trigger: BEFORE INSERT create table tt(id int, name varchar(20), value int); create table t2(id int); CREATE TRIGGER trg BEFORE INSERT ON tt REFERENCING NEW as newrow FOR EACH ROW BEGIN ATOMIC INSERT INTO t2 (id) values (newrow.id); END insert into tt values(1, 'a', 10); insert into tt values(2, 'b', 20); insert into tt values(3, 'a', 30); insert into tt values(4, 'a', 40); The result vales in t2 are: After insert#1: EMPTY After insert#2: {1} After insert#3: {1, 1, 2} After insert#4: {1, 1, 2,1,2,3} Tested this in Mysql and the same trigger works well there. Expected t2 values after insert#4: {1,2,3,4} Regards, Tapomay.