Qs. What are the advantages of column-based tables?
Only affected columns have to be read during the selection process of a query. Any of the columns can serve as an index.
Columnar data storage allows highly efficient compression because the majority of the columns contain only few distinct values (compared to number of rows).
- Better parallel Processing
In a column store, data is already vertically partitioned. This means that operations on different columns can easily be processed in parallel. If multiple columns need to be searched or aggregated, each of these operations can be assigned to a different processor core