Drill-down feature is at OLAP or BI layer?

Question

Drill-down, by definition, requires the use of hierarchical data where values are grouped into levels. (reference)

My understanding of drill-down feature is provided by OLAP engine (e.g. Clickhouse, Apache Druid, Apache Pinot etc) and not BI/Visualisation tool (e.g. Tableau, Superset, Grafana etc). However from this presentation slides Seeing Is Believing: Popular BI Tools for ClickHouse (link), it said Grafana supports interactive drill-down on data but not Superset.

My questions:

1. Drill-down feature is at OLAP or BI layer?
2. Does drill-down feature require pre-computed dimensional aggregations?
3. How dimensions that can be drilled down are identified? Manually or automatically?

Thanks.

Answer 1

Drill-down feature is at OLAP or BI layer?

Not sure what you mean by the both... but you might check the response to the third question.

Does drill-down feature requires pre-computed dimensional aggregations?

Not necessarily. For example, icCube is computing the aggregated values on-the-fly while processing a query; whether it is related to a drilldown or not does not matter at all.

How dimensions that can be drilled down are identified? Manually or automatically?

The visualization tools should somehow know that a dimension exists and that the members of that dimension (e.g., a country, a year) have some children (e.g., cities, quarters) and have a way to query those children. This is automatic for client tool (e.g., Excel, Tableau) connecting for example to icCube, SSAS, ... Those tools are able to discover the dimensions structure first.