Referential join integrity

[Former Member]

Hi HANA experts,

I have a question regarding the referential join integrity.I have seen two statements as following, which one is correct?

1 Each entry in the left table must have a correspondingentry in the right table.

2 For each row in one table, there is at least one join partner in the other table, and that holds true in both directions at all times.

Obviously statement 2 is more restricted. However if statement 1 alone is sufficient  to do a valid referential join?

Thanks,

[Former Member]

Technically from a join perspective both the statement are same the first one will need a referential join but no defined cardinality and the second one is a referential join with a 1:N cardinality..

To answer your query you are right the statement 1 is sufficient condition to have a referential join..

[Former Member]

Thanks Mishra,

In that case even there are rows in right table that don't have corresponding rows in left table it is still a valid reference join as long as statment 1 is met?

Cheers,