SamplePowerRequirementHistorizedData
| fork
    Dataset2 = (where twinId  <> "p_sol_01" | summarize count() by twinId, name)
    Dataset3 = (summarize count() by WeekOfYear = week_of_year(timestamp))

It is possible to use almost all the known features of the KQL language inside every single “sub” result set. For instance, the join operator inside a sub-statement does not work. This is not allowed by the engine.