clickhouse-client --query_kind secondary_query -q explain plan header=1 select toString(dummy) as dummy from system.one group by dummy
Expression ((Projection + Before ORDER BY))
Header: dummy String
  Aggregating
  Header: toString(dummy) String
    Expression (Before GROUP BY)
    Header: toString(dummy) String
      ReadFromStorage (SystemOne)
      Header: dummy UInt8
clickhouse-local --query_kind secondary_query -q explain plan header=1 select toString(dummy) as dummy from system.one group by dummy
Expression ((Projection + Before ORDER BY))
Header: dummy String
  Aggregating
  Header: toString(dummy) String
    Expression (Before GROUP BY)
    Header: toString(dummy) String
      ReadFromStorage (SystemOne)
      Header: dummy UInt8
clickhouse-client --query_kind initial_query -q explain plan header=1 select toString(dummy) as dummy from system.one group by dummy
Expression ((Projection + Before ORDER BY))
Header: dummy String
  Aggregating
  Header: toString(dummy) String
    Expression (Before GROUP BY)
    Header: toString(dummy) String
      ReadFromStorage (SystemOne)
      Header: dummy UInt8
clickhouse-local --query_kind initial_query -q explain plan header=1 select toString(dummy) as dummy from system.one group by dummy
Expression ((Projection + Before ORDER BY))
Header: dummy String
  Aggregating
  Header: toString(dummy) String
    Expression (Before GROUP BY)
    Header: toString(dummy) String
      ReadFromStorage (SystemOne)
      Header: dummy UInt8