Question

In a columnar database, the columns are stored together on disk, achieving a higher compression ratio is an expensive operation

Answer 1

Column oriented databases are suitable for analytical workloads as it has the data format lends with faster query processing that especially scans and aggregation.

The Columnar databases stores the data to a single column together disk or in-memory or both. Row oriented databases stores the single row contiguously and goes over all values of a particular.