Tablespace Allocated Space (MB)


This is a database-level metric. For cluster databases, this metric is monitored at the cluster database target level and not by member instances.

The allocated space of a tablespace is the sum of the current size of its data files. A portion of this allocated space is used to store data while some may be free space. If segments are added to a tablespace, or if existing segments grow, they will use the allocated free space. The allocated free space is only available to segments within the tablespace. If, over time, the segments within a tablespace are not using this free space, the allocated free space is not being used.

This metric calculates the space allocated for each tablespace. It is not intended to generate alerts. Rather it should be used in conjunction with the Allocated Space Used (MB) metric to produce a historical view of the amount of space being used and unused by each tablespace.

Metric Summary

The rest of the information in this section is only valid for this metric when it appears in either the Enterprise Manager Grid Control or the Enterprise Manager Database Control (if applicable).

The following table shows how often the metric's value is collected.

Target Version

Collection Frequency

All Versions

Every 7 Hours

Data Source

Tablespace Allocated Space (MB) is calculated by looping though the tablespace’s data files and totalling the size of the data files.

User Action

Specific to your site.

Related Topics

About Alerts

About the Metric Detail Page

Editing Thresholds

Understanding Line Charts