[manigandham]

Clickhouse/Druid/Pinot are all columnstores/column-oriented databases. Clickhouse is a relational engine while Druid/Pinot are a different (and older) design using heavy indexing and pre-aggregation. All of them store table data as per-column segments though which is a defining feature leading to high compression and I/O performance.

There's also the badly named wide-column database type like Cassandra, but this is really just advanced or nested key/value rather than what people would consider "columns".