Question: What
do I do to reclaim the spaced used when I shrink the size of
a BLOB or LOB column within a table?
We configured a scheduled job to update BLOB Column to
EMPTY, This Job runs every night and update 30 days old
rows.
update
my_tab
set
event_data =
empty_blob();
Despite this we can see
spike in tablespace usage, How do I shrink the
row lengths?
Answer: The LOB/BLOB column still
exists within the table blocks, and the data is still there.
It is only marked as unused. To free up the space, use
this command:
alter table
my_tab
modify lob
event_data
(shrink space);
Remember, you must shrink lob or move, after updating
column as null or empty_blob. For a partitioned table,
use this syntax:
alter table
ev_log modify
partition
part_1
lob
(event_data)
(shrink space);
|
|
|
|
|
Oracle Training from Don Burleson
The best on site
"Oracle
training classes" are just a phone call away! You can get personalized Oracle training by Donald Burleson, right at your shop!
|
|
|
|
| |
|
Burleson is the American Team
Note:
This Oracle
documentation was created as a support and Oracle training reference for use by our
DBA performance tuning consulting professionals.
Feel free to ask questions on our
Oracle forum.
Verify
experience!
Anyone
considering using the services of an Oracle support expert should
independently investigate their credentials and experience, and not rely on
advertisements and self-proclaimed expertise. All legitimate Oracle experts
publish
their Oracle
qualifications.
Errata?
Oracle technology is changing and we
strive to update our BC Oracle support information. If you find an error
or have a suggestion for improving our content, we would appreciate your
feedback. Just
e-mail:
 and include the URL for the page.
Copyright © 1996 - 2020
All rights reserved by
Burleson
Oracle ®
is the registered trademark of Oracle Corporation.
|
|
