MVCC and all that...

Reading this article
https://firebirdsql.org/migrating-from-firebird-to-postgresql-what-can-go-wrong-
I'm a bit confused (not the first time...)

In part 1. Differences in MVCC implementation - he's saying that "It’s
not that the PostgreSQL implementation of MVCC is bad — it’s just
fundamentally different"

But, I thought Firebird had SWEEP instead of VACUUM (how much closer
can the words be?) and that FB's implementation of MVCC was
essentially similar.
Is this correct? Then why is he pointing out the performance diffs
because of MVCC? I'm puzzled!


--

El!