Cascading: Merge tuple if Join is unavailable

Question

Here's my issue:

I have two tables with an ID field to match on. Most of them will match, but if the don't, I need to merge that record to the other table and make the empty fields null.

Is this kind of thing possible in cascading?

Thanks!

Answer 1

Merge can be used only to merge tuples with same layout. You can use CoGroup or HashJoin. If your right pipe is small enough to fit in memory then HashJoin is better than CoGroup. For large dataset better to use CoGroup.

Answer 2

You can use a CoGroup along with Left/Right/Outer join that matches your requirement.