I implemented a scenario in which I used source -> query -> table_comparison -> target. In target I added Cust_gen column and after job execution I found that it contains null values which is correct as I have not added any key generation transform to get the values.
Now after this I added Key generation transform to check how it actually works and added a row in source and after execution of job i found that cust_gen column has a set of values for every record but I have read that it looks for maximum existing value and then assigns value to newly inserted records. So as per my understanding the maximum value in source is 501 and the value of cust_gen should start from 501.
Can someone please help me that how does this Key generation transform works and also why every record has got values of cust_gen.