Postgres code for a query intermediate dataset

Hi All,

I want to work on the code of intermediate dataset of select and update query.

For example.

Rohit's salary has been updated 4 times, so it has 4 different version of salary.

I want to select  salary of person named Rohit. Now suppose , in intermediate result, I found 4 different versions of the data. I want to know the code portion which i need to look for working on all 4 versions in dataset. :)

Thanks in advance!!
Regards,