What is "Aggregation" in SQL?

Question

Mark all correct statements about aggregation in relational databases.

Answer 1

Aggregation changes the level of detail (granularity) of a dataset, transforming atomic, row-level data into high-level metrics.

Answer 2

An aggregate is a summary statistic computed over a group of data - such as totals, averages, counts, minimums, maximums, or string concatenations.

Answer 3

Aggregation possible only for numbers