thanks Moff,
but I had tried that already and it does not help, though.
Considering my datafile layout and their sizes, do you think there is any error in specifying 256 numbers of subpartitions? I mean if each subpartion will be allocated initially one extent of 1772M then obviously there is not so much space present(available is 1796 M X 8 files).So, if this is the error then i should be able to create a table with 256 subpartitions but having initial extent of less than 1796 X 8/256 say around 56 M only instead of 1772M as I am trying to do?
Manjunath