what aspects should I take into consideration after I delete a large amount of data from a table

  my oracle version is 9.2.0.8. Now I want to get rid of some rows from  a normal table (not IOT table). Because this table has more than 90 million rows, and it is a critical table in my producation enviornment, I will analyse the impact of deleting rows before I do it.

   Now I think there are three aspacts :

    1. the index need to be rebuilded after the deleting, because there will be fragment of index;

    2. the high-water-mark will be changed, I need  deal with it.

   3. the statistics of the table will be changed, I need calculate the statistics of the table again.