0

I am new to Oracle, and I am not quite understanding the size calculations shown in OEM under tablespaces. I know it should be simple and my well be.

I need to monitor the table space but not sure what I am looking at. Should I go after the "Available Space Used(%) or the Allocated Space Used(%) to monitor?

If I am running a script to alert when a threshold is met, which % should I use?

enter image description here

1 Answer 1

0

"Allocated Space Used(%)" reports the utilization of a tablespace based on the current size of its datafiles. Typically the value of this metric is close to 100% which causes a lot of false positive alerts.

Go after "Available Space Used(%)". That reports the utilization of a tablespace based on the configured maximum size of its datafiles (and the available free space in the filesystem or ASM diskgroup).

Example:

Tablespace TS1 consist of a single datafile that is 10 GB and contains 10 GB data. The datafile is configured as autoextensible with a maximum size of 20 GB. The single datafile of TS1 is on a filesystem with more than 10 GB free space.

"Allocated Space Used(%)" - 100%
"Available Space Used(%)" - 50%

If the single datafile of TS1 is in a filesystem with only 5 GB free space:

"Allocated Space Used(%)" - 100%
"Available Space Used(%)" - 66.6%
1
  • Thank you Balazs.. That is exactly what I needed. This looks to be safe just using a "select tablespace_name, used_percent from dba_tablespace_usage_metrics". That percent used lines up with Available Space Used in OEM. Thank you again!! Dec 28, 2023 at 23:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.