Why joiner doesn't have not equal to operator in Informatica?

Question

Why doesn't Informatica's joiner transformation support !=, >=, <= operators?

Why should they come up with a concept like lookup?

Answer 1

Joiner transformation is used for vertical consolidation. e.g

order-tbl
order-id, item-id, item-qty

item-tbl
item-id, item-price, item-desc

Using a join condition on order-tbl.item-id = item-tbl.item-id you could print a report like this

order-id, item-id, item-price, item-desc

For vertical consolidation, I can't think of a scenerio needing other conditions like !=, >=, <=.

With lookup transformation, some core ETL tasks are made easy like

1. identifying if the incoming record is a new record (primary key doesn't exist) or an update to the existing record;

2. lookup a value e.g. lookup item-price from item-tbl to calculate order total.