7 、shrink table and its dependent segments

To shrink table and its dependant segments,you should use the ALTER TABLE ** SHRINK SPACE CASCADE;statement .Using the CASCADE clause shrinks all the dependant segments of the ** table to release the unused space below and above the High Water Mark(HWM).[@more@]

The table should be located in a tablespace on which automatic segment space management is enabled.If the table is loacted in a tablespace on which manual segment space management is enabled,you cannot shrink the table.