We use the LINEITEM relation from the TPC-H benchmark at scale factor 0.1

     lORDERKEY : 1
      lPARTKEY : 15519
      lSUPPKEY : 785
   lLINENUMBER : 1
     lQUANTITY : 17
lEXTENDEDPRICE : 24386.67
     lDISCOUNT : 0.04
          lTAX : 0.02
   lRETURNFLAG : N
   lLINESTATUS : O
     lSHIPDATE : 1996-03-13
   lCOMMITDATE : 1996-02-12
  lRECEIPTDATE : 1996-03-22
 lSHIPINSTRUCT : DELIVER IN PERSON
     lSHIPMODE : TRUCK
      lCOMMENT : blithely regular ideas caj


query LINEITEM feedproject[lORDERKEY, lPARTKEY, lSUPPKEY, lLINENUMBER, 
lQUANTITY, lEXTENDEDPRICE, lDISCOUNT, lTAX, lRETURNFLAG, lLINESTATUS, 
lSHIPDATE] count


13.86, 13.66, 13.61 sec

Estimate 16.76


query LINEITEM feedproject[lORDERKEY] count

2.95, 2.96, 2.95

Estimate 5.95


Time difference is 13.66 - 2.96 = 10.7

Time per attribute is 10700 / (10 * 600572) ms = 0.0018


let LINEITEMFirstAttr = LINEITEM feedproject[lORDERKEY] consume


query LINEITEMFirstAttr feedproject[lORDERKEY] count

2.32, 2.32, 2.32

Estimate 2.39


let LINEITEM10 = LINEITEM feed ten feed product remove[no] consume

let LINEITEMFirstAttr10 = LINEITEMFirstAttr feed ten feed product 
remove[no] consume



query LINEITEM10 feedproject[lORDERKEY] count

57.22, 60.26, 58.39

Estimate 59.5

Tuplesize is 169.8


query LINEITEMFirstAttr10 feedproject[lORDERKEY] count

25.70, 22.70, 22.88

Estimate is 23.9

Tuplesize is 5


Time difference is 58.5 - 22.8 = 35.7

Difference in number of bytes is 164.8 * 6005720

Time per byte is 35700 / (164.8 * 6005720) = 0.036 mikrosecs 
	= 0.000036 ms per byte


For this query:

	query LINEITEMFirstAttr10 feedproject[lORDERKEY] count

total time for bytes is 6005720 * 0.000036 = 0.216 sec

total time for attrs is 6005720 * 1 * 0.0018 = 10.81 sec

Remaining time is 22.8 - 11 = 11.8 sec 

	is 11800 / 6005720 = 0.002 ms per tuple




Estimates for small relations are a bit too large because time 
per byte is measured for reading large relations from disk (not buffered).