If we can't manage we'll eventually do something else for timeseries data - eg, we could do a Foreign Data Wrapper to Clickhouse tables
By the way I can see there are some already but I do not use them https://github.com/Infinidat/infi.clickhouse_fdw/ https://github.com/adjust/clickhouse_fdw
It would be beneficial to couple transactional data (Postgres) with OLAP data (CH). There are a few other things coming in PG which might mitigate the need for CH too (pluggable storage, zheap), so we're not going to rush this part.
If we can't manage we'll eventually do something else for timeseries data - eg, we could do a Foreign Data Wrapper to Clickhouse tables