Space used by tables

Question

in a production environment we are short of disk space. we need to know which tables are occupying the high amount of space from all the tablespaces present in the database, so that we can delete some data (if possible ) from those tables. any sql query to do this task in short amount of time.
Thanx in Advance.

Answer 1

Hi Abhishek,
"Seeking help is not a frailty".
Below query might help you.
COLUMN TABLE_NAME FORMAT A32
COLUMN OBJECT_NAME FORMAT A32
COLUMN OWNER FORMAT A10
SELECT owner, table_name, TRUNC(sum(bytes)/1024/1024) Meg
FROM (SELECT segment_name table_name, owner, bytes
FROM dba_segments WHERE segment_type = 'TABLE'
UNION ALL
SELECT i.table_name, i.owner, s.bytes
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name AND s.owner = i.owner AND s.segment_type = 'INDEX'
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name AND s.owner = l.owner AND s.segment_type = 'LOBSEGMENT'
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name AND s.owner = l.owner AND s.segment_type = 'LOBINDEX')
WHERE owner in UPPER('&owner') GROUP BY table_name, owner HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */ ORDER BY SUM(bytes) desc ;
Thanks and Regards,
Auroeis
Edited by: 939781 on Jun 27, 2012 2:19 AM