tmap cross join question

[Anonymous]

From the screenshot i don't see any link between row1 and row2 in tmap. what kind of join is this? so far I saw a join condition(inner join) and a link. In this case it says left outer join but on what condition is the big question. From what i see my data does  not match on those columns. Even if this is a cross join there should be a matching condition but in this case there is none. I am having hard time trying to decode this to Sql. Any help on this is greatly appreciated. 

[David_Beaty · Accepted solution]

Hi,

Its giving you the Cartesian product of both sources. The "Left outer join" is part of the join model, which you have no join, so is somewhat obsolete. For each individual flow in row1.....every entry in row2 will be matched.

[Anonymous]

Thank you very much. This helps. 

[Anonymous]

A tMap is driven by one input source, the main source. In your case that is row1. Any other source is just for lookups. If you are not joining, then you will get every row of the lookup "matched" against every row of the main IF "Match Model" is set to "All rows". What you have there does look like a cross-join. You do not need a join condition on a cross-join as it is the Cartesian product.

[Anonymous]

Sorry @dsoulalioux, it appears I started my response before you started yours and then got involved in something else before posting 🙂 Nice answer