i have a big table ( 10 GB ) which has an index on a number field. Index is almost same size as the table and I want to rebuild the index the database is very active and the table is also very active read about 100K times in 20 minutes and few writes as well. I want to know during the index rebuild process, does oracle allow writing to the table ( insert into that table) ? Please let me know, i am kind of lazy to do test. Thanks Deen