Query to Check Installed component in the oracle database?

Here are the two queries to find out the installed components in the oracle database. 

set pages 1000 lines 120 

col comp_name for a40 

1. select comp_name, version, status , modified from dba_registry; 

2. select parameter from v$option where value = 'TRUE' order by parameter; 

Purge AWR Snapshots Manually from Oracle Database

Query to find AWR snapshot retention period using below query.

SQL> select dbms_stats.get_stats_history_retention from dual;

GET_STATS_HISTORY_RETENTION
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			 31