1. Database Object Information:
Select owner,object_type,count(*) from dba_objects Where owner not IN ('SYS','MDSYS','CTXSYS','HR','ORDSYS','OE','ODM_MTR','WMSYS','XDB','QS
_WS', 'RMAN','SCOTT','QS_ADM','QS_CBADM', 'ORDSYS','OUTLN','PM','QS_OS','QS_ES','ODM','OLAPSYS','WKSYS','SH','SY
STEM','ORDPLUGINS','QS','QS_CS')
Group by owner,object_type order by owner;

2. Query to Find 5 largest object in Database:
SELECT * FROM (select SEGMENT_NAME, SEGMENT_TYPE, BYTES/1024/1024/1024 GB, TABLESPACE_NAME from dba_segments order by 3 desc ) WHERE ROWNUM <= 5;

3. Count Invalid Object:
Select owner, object_type, count(*) from dba_objects where status='INVALID' group by  owner, object_type;