Tell me what you know about columnar and row-based data storage. When and which one should be chosen and why?

Row-oriented storage saves data row by row, meaning all fields of a single record are stored together, which is efficient for transactional systems with frequent insert and update operations.

Column-oriented storage saves data by columns, which speeds up analytical queries that read and aggregate specific fields of large datasets.

The choice depends on the task: for OLTP systems and frequent operations on individual records — row-oriented storage; for OLAP and big data analytics — column-oriented storage, as it reduces the amount of data read and speeds up aggregations.