Subquery Outputs: How Results Are Used

The results of a subquery are used in different ways depending on the function:

Select events or elements — The subquery filters or selects specific events or array elements based on conditions.
Example contexts: array:filter(), selfJoinFilter()
Compute values — The subquery calculates a value for each input event or element.
Example context: array:eval()
Select and transform events — The subquery retrieves and transforms events for use in the main query.
Example contexts: defineTable(), correlate()
Perform aggregations — The subquery aggregates data and returns summary results.
Example contexts: array:reduceAll(), array of subqueries in groupBy()