Full disclosure: I am CTO of QuestDB and I took part in JIT implementation. The quote above is not mine, it was written by Clickhouse staff. "utilizes its full indexing strategy" statement is false and is news to me.

So you do a full scan and it's ~50 CPU cycles per row (48 CPUs at 4 GHZ), correct? This is possible I guess? And in this case Clickhouse is wrong.

So, QuestDB is faster or not? I'm puzzled now!

Looks like QuestDB is faster if you don't optimize your table storage for 1 query.

But if you are okay that only limited number of columns to be scanned faster than others ClickHouse comes first.