Question regarding lob column
Date: Wed, 06 May 2009 12:56:08 -0800
We have a table that has a lob column. The table is in tablespace A, the lob storage is in tablespace B (with an associated index).
Every month a job runs and adds more data to this table, so we've had to add datafiles on a regular basis. Now the user wants to delete some data so we don't have to keep adding datafiles, but can reuse some of the space that's already been allocated to the tablespaces.
So, I got a rowcount from the table before the user deleted anything, and I also got the bytes and extents values from dba_segments for the tablespaces.
The user then proceeded to delete at least 1/3 of the rows in the table. When I did my queries again, the rowcount had changed as expected, but the bytes and extents values didn't change for the segments in dba_segments. There were 172 extents before and there are 172 extents after the delete.
Any ideas as to why no extents appear to have been freed up?
We don't have Grid Control or EM available, so I can't see any pictures of space usage....