thx Martin , but my problem is that i added manually rows in my database , and i want to know if it will cause a collision or not in the future , So i have a doubt if activiti engine use the sequence to generate ids ? i saw the function getNextId in DbIdGenerator but i did not undersand how activiti engine generate ids .
There are 2 implementations of Id generators in activiti sources. org.activiti.engine.impl.db.DbIdGenerator org.activiti.engine.impl.persistence.StrongUuidGenerator
Based on configuration you can use one of them (or your own). org.activiti.engine.impl.db.DbIdGenerator uses property table row next.dbid to get blocks of free ids. (org.activiti.engine.impl.cmd.GetNextIdBlockCmd)