Yes, so infact i lost a datafile hence a table on this one is lost also so in the dictionary still keep infomation about it, for this reason i want to drop directly some extents of that (update table uet$ & fet$ ) ?? and i don't want to ex-import this table (90G)
If it's 8.i you can rebuild your table online with new storage parameters. If it's realy big (90G, as you say) then I suppose finding sufficient free space for this will be a problem, I suppose. For such a big table partitioning is recomended anyway, if not for performance then definitively for managability - tasks like this you are facing now.
If you are not on 8i yet (or even if you are) and you have a lot of free space above the highwattermark of this table (that is, a lot of unused space at *the end*) of that segment you can free this space with ALTER TABLE ... DEALOCATE UNUSED.
Otherwise you have no other choice than to rebuild with exp/imp.
Jurij Modic ASCII a stupid question, get a stupid ANSI
24 hours in a day .... 24 beer in a case .... coincidence?