rcount = dt / xx3

     str = "select cdate(avg(dat)) as dat_sr, max(param) as param_mx, min(param) as param_mn From tabl1 where dat between #" _

& Format(dt1, "mm\/dd\/yyyy hh:mm:01") & "# and #" & Format(dt2, "mm\/dd\/yyyy hh:mm:02") & "# group by fix(cdbl(dat)/cdbl(timeserial(0,0," & rcount & ")))  ;"

str = "select * From tabl1 where dat between #" & Format(dt1, "mm\/dd\/yyyy hh:mm:01") & "# and #" & Format(dt2, "mm\/dd\/yyyy hh:mm:02") & "# order by dat ;"

int step = DataCount/Width; // 60 000 / 1 024 = 58

for(int i=0;i<DataCount;i+=58){ // только каждый 58 элемент!

...

}

For i=0 to DataCount

...

i = i+57

next i

select ..., max(value) as value

from ...

where ...

group by fix(@pixel_cols_count * (dt - @start_dt) / (@end_dt - @start_dt))