删除Postgres中某个行号的行

I am building an app in which I need to delete a table row at a certain line number. I don't want to use or rely on an id, because if I delete a row, the following rows won't "shift down" -- line 8 today could be line 7 tomorrow, but line 8 will still have an id of 8. I am building an app in which I need to delete