POSIXct    :   firstStream_byUCnDPMb,   lastStream_byUCnDPMb,
                firstStream_byUCnDP,     lastStream_byUCnDP

 logical    :   mobile,                  isLastOccurOfUser_perD,
                isFirstOccurOfUser_perD
 ----------------------------------------------
 POSIXct    :   firstStream_byUCnDPMb,   lastStream_byUCnDPMb,
                firstStream_byUCnDP,     lastStream_byUCnDP,
                firstStream_byUCnD,      lastStream_byUCnD

 logical    :   mobile,                    isLastOccurOfUser_perD,
                isFirstOccurOfUser_perD,   isFirstStream_byUCnD,
                isLastStream_byUCnD


cUsing <- 
c("userid", "month", "country", "product", "mobile"
  , "isFirstOccurOfUser_perD", "isFirstStream_byUCnD", "firstStream_byUCnD", "firstStream_byUCnDP", "firstStream_byUCnDPMb"
  , "isLastOccurOfUser_perD", "isLastStream_byUCnD", "lastStream_byUCnD", "lastStream_byUCnDP", "lastStream_byUCnDPMb")

DT.Sampl.u[.("0000023b43b307354943ae74caff3886", "DE", as.Date("2013-04-01")), cUsing, with=FALSE]

DT.Sampl.u[.("3754da008362fd48d33e80bb3e628335", c(unique(country)), as.Date("2013-05-01")), cUsing, with=FALSE, nomatch=0L]

DT.Sampl.u[.("3754da008362fd48d33e80bb3e628335")][, cUsing, with=FALSE]
DT.Sampl.u[.("3754da008362fd48d33e80bb3e628335")][isFirstStream_byUCnD != isFirstOccurOfUser_perD, cUsing, with=FALSE]

testing <- DT.Sampl[.("3754da008362fd48d33e80bb3e628335"), c(kCols_UCnD, "lastStream_byUCnDPMb", "firstStream_byUCnDPMb"), with=FALSE] 


-------------


cUsing <- 
c("userid", "month", "country", "product", "mobile"
  , "isFirstOccurOfUser_perD", "isFirstStream_byUD", "firstStream_byUD", "firstStream_byUCnDP", "firstStream_byUCnDPMb"
  , "isLastOccurOfUser_perD", "isLastStream_byUD", "lastStream_byUD", "lastStream_byUCnDP", "lastStream_byUCnDPMb")

DT.Sampl.u[isFirstStream_byUD != isFirstOccurOfUser_perD, cUsing, with=FALSE]
DT.Sampl.u[isLastStream_byUD != isLastOccurOfUser_perD, cUsing, with=FALSE]


DT.Sampl.u[.("00000c79adcd9d1572cf74603e6b7152", as.Date("2013-09-01")), cUsing, with=FALSE]

DT.Sampl.u[.("3754da008362fd48d33e80bb3e628335", as.Date("2013-05-01")), cUsing, with=FALSE, nomatch=0L]

DT.Sampl.u[.("3754da008362fd48d33e80bb3e628335")][, cUsing, with=FALSE]

testing <- DT.Sampl[.("3754da008362fd48d33e80bb3e628335"), c(kCols_UD, "lastStream_byUCnDPMb", "firstStream_byUCnDPMb"), with=FALSE] 





unique(testing)
unique(testing, by=key(testing))
unique(testing, by=NULL)
unique(testing, by=names(testing))


unique(
  )[order(lastStream_byUCnDPMb)]

DT.Sampl[][isFirstStream_byUCnD != isFirstOccurOfUser_perD]


838: 3754da008362fd48d33e80bb3e628335 26
839: 375b8f4f67c10580d1d692eda612c0f8 27
840: 3742a8e972febcf87362f4eb0e3cea32 28
841: 375b7b59ae49b9c4570bc7b184d00c79 30
842: 37428a800c9d00d3c534ada8d99822dd 45