anchor.diff:          | Ok series ->
               let serie = Seq.single series
               serie.Name =? data.Measurement
  -            serie.Tags =? data.Tags
  -            serie.Columns =? ["time"; "external"; "internal"]
  +            serie.Tags =? Map.empty     // query without GROUP BY, all tags transformed into values
  +            serie.Columns =? ["time"; "external"; "internal"; "machine"; "type"]
               let values = Seq.single serie.Values
  -            values =? [| String (fmtTimestamp timestamp); externalVal; internalVal |]
  +            values =? [| String (fmtTimestamp timestamp); externalVal; internalVal; machine; typ |]
           | Fail msg -> failwithf "Query result error: %s" msg
       | x -> failwithf "unexpected results: %A" x
   
   [<Explicit>]
   [<Property(Arbitrary=[|typeof<Generators>|])>]
  +// this test generates some data that influxdb 0.9.2 start hangs
  +// I should try it on later versions and report possible issues
   let ``write point then query it back [FsCheck]`` (data: PointData) =
       let db = integrationDbs.[0]
       let client = Client(machine, proxy = fiddler)
  
positive.code:     // check temperature
      let temperatureSerie = querySingle "SELECT * FROM temperature"
      temperatureSerie.Name =? temperatureData.Measurement
      temperatureSerie.Tags =? temperatureData.Tags
      temperatureSerie.Columns =? ["time"; "external"; "internal"]
      let temperatureValues = Seq.single temperatureSerie.Values
      temperatureValues =? [| String (fmtTimestamp timestamp); temperatureExternal; temperatureInternal |]
  
      // check cpu_load_short
      let cpuSerie = querySingle "SELECT * FROM cpu_load_short"
      cpuSerie.Name =? cpuData.Measurement
      cpuSerie.Tags =? cpuData.Tags
      cpuSerie.Columns =? ["time"; "value"]
      let cpuValues = Seq.single cpuSerie.Values
      cpuValues =? [| String (fmtTimestamp timestamp); cpuLoad |]
  
  [<Test>]
  let ``query have wrong syntax => error in response`` () =
  
negative.code:     let timestamp = DateTime.UtcNow
      let internalVal = Int 32L
      let externalVal = Int 100L
      let machine = String "unit42"
      let typ = String "assembly"
  
      let data = { Measurement = "temperature"
                   Tags = Map [ "machine", "unit42"; "type", "assembly" ]
  