Hello Chris, The global table described in KIP-99 will keep the most recent snapshot of the table when applying updates to the table, i.e. it is like type 1: overwrite. So when a table or stream is joined with the global table, it is always joined with the most recent values of the global table.
However, note that in Kafka Streams api, joining streams are synchronized based on their incoming record's timestamps (i.e. the library will choose which records to process next, either from the global dimension table's changelog, or from the fact table's changelog, based on their stream time in the best effort), so if you have an updated value on the fact table, that update's timestamp will be aligned with the the current updates on the global table as well. Guozhang On Mon, Oct 16, 2017 at 12:51 PM, chris snow <chsnow...@gmail.com> wrote: > The streams global ktable wiki page [1] describes a data warehouse syle > operation whereby dimension tables are joined to fact tables. > > I’m interested in whether this approach works for type 2 slowly changing > dimensions [2]? In type 2 scd the dimension record history is preserved > and the fact table record is joined to the appropriate version of the > dimension table record. > > — > [1] > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > 99%3A+Add+Global+Tables+to+Kafka+Streams > [2] https://en.m.wikipedia.org/wiki/Slowly_changing_dimension > -- -- Guozhang
