Hoi, I searched the archives but couldn't find an answer to this: I have a table (simplyfied) CREATE TABLE test ( id INT PRIMARY KEY, name VARCHAR(250) ); I insert records with INSERT INTO test (id, name) SELECT COALESCE(MAX(id)+1, 1), 'name' FROM test Ofcourse this gives problems when two clients are inserting a record at the same time. (duplicate primary keys) But, i can't use a sequence in my application (the pk consists of more than just a sequence) one solution would be to do a 'LOCK TABLE test IN SHARE MODE' before inserting. This solves my problem but i'm not sure if its the best way to deal with this kind of concurrency problems ? Is there a better way ? Thanks in advance. Ralph. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster