Hi, I have to delete many millions of records from different tables periodically. I can't use CTAS to do this. I use block record delete. In tests I noticed that the index table space (we have one table space for data and one for indexes) does not decrease after delete the records. Doesn't it decrease because the spaces are still occupied or does it have free spaces that Oracle blocks for future allocations?
On the other hand, if at the end of the process I rebuild the indexes, the size of the tablespace decreases. Am I always forced at the end of the process to rebuild the indices? (It is a matter of time, the whole process must end in a certain time, if I have to rebuild the indexes then it gets complicated).
Thank you