ADDM components

SQL Tuning Advisor:
Provides tuning advice for SQL statements

SQL Access Advisor:
Deals with schema issues and determines optimal data access paths,such as indexes and materialized views

Segment Advisor:
Monitors object space issues and analyzes growth trends

this graph will explain more:

delete(recreate) the dbconsole and repository of OEM

maybe you would get a momnet of failure of OEM when upgrade the rdbms,work as below to retry it

recreate OEM(OEM recreation will be done at the end of upgrade)

delete the dbconsole and repository of OEM
/u01/app/oracle/product/10.2.0/db_1/bin>emca -deconfig dbcontrol db -repos drop

recreate the dbcontrol and repository of OEM
/u01/app/oracle/admin/anqing/bdump>emca -config dbcontrol db -repos create

ORA-19815: WARNING: db_recovery_file_dest_size

you have four options to solve this ORA-19815 case,just work as follow

You have the following choices to free up space from flash recovery area:
1. Consider changing your RMAN retention policy.
If you are using dataguard, then consider changing your
RMAN archivelog deletion policy.
2. Backup files to tertiary device such as tape using the
RMAN command BACKUP RECOVERY AREA.
3. Add disk space and increase the db_recovery_file_dest_size
parameter to reflect the new space.
4. Delete unncessary files using the RMAN DELETE command.
If an OS command was used to delete files, then use
RMAN CROSSCHECK and DELETE EXPIRED commands.