SCD for PostgreSQL

How would I build a SCD if my target database is PostgreSQL? It doesn’t look like it is an option for PostgreSQL? Is the Diff Snap the way to do it?

For anyone wondering, I’m using a Join Snap with an Outer Join.

If a unique ID field from the left side is null but populated on the right side then it is a deleted record.
If a unique ID field from the left side is populated but null on the right side then it is a new record.
If a unique ID field from the left side and right side are both populated then the it is an existing record.