A space monitering script is running too slowly !! How can I make it faster

Question

Hi. all.
The following db space monitering script is really taking too much time.
The script is from a certain db monitering solution.
It is running on a 30-minute regular basis, and one of top sqls from AWR reports.
As you know, "dba*" objects are not a physical table.
I would like to know how to figure out this performance issue..
The database is oracle 10.2.0.4 on a solars, and has about 110 tablespaces and 2300 data files.
The total size of the database is about 36 Tera size.
SELECT a.tablespace_name || ' ' || ROUND ( (a.used_bytes - NVL (b.recycle_bytes, 0)) / a.total_bytes * 100, 2) USAGE
FROM (SELECT t.tablespace_name, SUM (u.BYTES) used_bytes, SUM (t.BYTES) total_bytes
FROM (SELECT tablespace_name, SUM (user_bytes) BYTES
FROM dba_data_files
GROUP BY tablespace_name) t,
(SELECT tablespace_name, SUM (BYTES) BYTES
FROM dba_segments
GROUP BY tablespace_name) u
WHERE t.tablespace_name = u.tablespace_name(+)
GROUP BY t.tablespace_name) a,
(SELECT ts.tablespace_name, SUM (rec.BYTES * df.block_size) recycle_bytes
FROM (SELECT file#, SUM (SPACE) BYTES
FROM SYS.recyclebin$
WHERE file# IS NOT NULL
GROUP BY file#) rec,
(SELECT ts#, file#, block_size
FROM v$datafile) df,
(SELECT tablespace_name, file_id
FROM dba_data_files) ts
WHERE rec.file# = df.file# AND df.file# = ts.file_id
GROUP BY ts.tablespace_name) b
WHERE a.tablespace_name = b.tablespace_name(+)
AND a.tablespace_name NOT IN (SELECT tablespace_name
FROM dba_rollback_segs
WHERE tablespace_name != 'SYSTEM')
Any help from your experience and knowledge will be greatly appreciated..
Thanks in advance.
Best Regards.

Answer 1

869578 wrote:
Hi. all.
The following db space monitering script is really taking too much time.
The script is from a certain db monitering solution.
It is running on a 30-minute regular basis, and one of top sqls from AWR reportsDo you suffer from Compulsive Tuning Disorder?
Is free disk space so small that you feel compelled to check it every THIRTY minutes?
My tablespaces are sized with approximately 2 months data growth is always free;
so I check them once a month to see if any need to be expanded more than previously allocated.