At the moment, it does it by not allowing updates at all.
It also forbids some parts of SQL that could get you update-like functionality, like appending new versions of records to a stream and then running
select * from (select *, row_number() over (partition by pk order by updated_at desc) from stream) where row_number = 1
or something.
(Boy I wish there was less awkward way to do this.)
EDIT: I'd love to ship bunch of data from few CDCs to Materialize and then run realtime reporting on that but without updates or window functions, Materialize can't do that just yet.
EDIT2: The part about updates isn't true, see below.
It also forbids some parts of SQL that could get you update-like functionality, like appending new versions of records to a stream and then running
or something.(Boy I wish there was less awkward way to do this.)
EDIT: I'd love to ship bunch of data from few CDCs to Materialize and then run realtime reporting on that but without updates or window functions, Materialize can't do that just yet.
EDIT2: The part about updates isn't true, see below.