Over time, updates and deletes on objects within a tablespace can create pockets of empty space that individually are not large enough to be reused for new data. This type of empty space is referred to as fragmented free space. Objects with fragmented free space can result in much wasted space, and can impact database performance. HFM consolidation performs extensive updates, inserts, and deletes, so it is very important to monitor the fragmentation of tablespaces and defragment them regularly. The preferred way to defragment and reclaim this space is to perform an online segment shrink. For more information about how to use online segment, refer to Oracle Database Administrator’s Guide.