Modifying collection schedule for OEM metric Tablespace Allocation.

Oracle DB 11.2, Standard Edition One with DB console.
Windows 2003 R2, 32bit

Default metric (Tablespace Allocation) collection interval is "Every 7 Days", which can be found on page "All Metrics" in DB console.

Go to %ORACLE_HOME%\sysman\admin\default_collection
and edit file database.xmlp

Find "Category: Tablespace Allocation" and few rows down:
      IntervalSchedule INTERVAL="7" TIME_UNIT="Day"

Change the interval number. Time unit can also be Hr or Min. Save the file.
Restart the oracle agent.
In this particular case by restarting windows service OracleDBConsoleSID, which bounces the agent as well.

"All Metrics" in DB console will still show 7 days interval. Check the real metric collection by the following SQL.
where METRIC_LABEL in ('Tablespace Allocation') and key_value='SYSTEM'
order by collection_timestamp desc;