DataBase Info & Helth Check....!!

******Total Size of The Database******

select
( select sum(bytes)/1024/1024/1024 data_size from dba_data_files ) +
( select nvl(sum(bytes),0)/1024/1024/1024 temp_size from dba_temp_files ) +
( select sum(bytes)/1024/1024/1024 redo_size from sys.v_$log ) +
( select sum(BLOCK_SIZE*FILE_SIZE_BLKS)/1024/1024/1024 controlfile_size from v$controlfile) "Size in GB"
from
dual ;

==============================================================
++++++++++++++++++++++++++++Total Size of The Database
col "Database Size" format a20
col "Free space" format a20
col "Used space" format a20
select round(sum(used.bytes) / 1024 / 1024 / 1024 ) || ' GB' "Database Size"
, round(sum(used.bytes) / 1024 / 1024 / 1024 ) -
round(free.p / 1024 / 1024 / 1024) || ' GB' "Used space"
, round(free.p / 1024 / 1024 / 1024) || ' GB' "Free space"
from (select bytes
from v$datafile
union all
select bytes
from v$tempfile
union all
select bytes
from v$log) used
, (select sum(bytes) as p
from dba_free_space) free
group by free.p
/
=========================================================================
+++++++++++++++++++++++++++++++largest objects in the database
SELECT * FROM ( select  SEGMENT_NAME, SEGMENT_TYPE, BYTES/1024/1024/1024 GB, TABLESPACE_NAME  from   dba_segments order by 3 desc  )  WHERE ROWNUM <= 10 ;

col owner format a15
col segment_name format a30
col segment_type format a15
col mb format 999,999,999
select owner
, segment_name
, segment_type
, mb
from (
select owner
, segment_name
, segment_type
, bytes / 1024 / 1024 "MB"
from dba_segments
order by bytes desc
)
where rownum < 11
/
=====================================
Show all connected users
set lines 100 pages 999
col ID format a15
select username
,      sid || ',' || serial# "ID"
,      status
,      last_call_et "Last Activity"
from   v$session
where  username is not null
order by status desc
,        last_call_et desc
/
============================
Time since last user activity
set lines 100 pages 999
select username
,      floor(last_call_et / 60) "Minutes"
,      status
from   v$session
where  username is not null
order by last_call_et
/
=======================
Sessions sorted by logon time
set lines 100 pages 999
col ID  format a15
col osuser format a15
col login_time format a14
select  username
, osuser
, sid || ',' || serial# "ID"
, status
, to_char(logon_time, 'hh24:mi dd/mm/yy') login_time
, last_call_et
from v$session
where username is not null
order by login_time
/
===========================
Show user info including os pid
col "SID/SERIAL" format a10
col username format a15
col osuser format a15
col program format a40
select s.sid || ',' || s.serial# "SID/SERIAL"
, s.username
, s.osuser
, p.spid "OS PID"
, s.program
from v$session s
, v$process p
Where s.paddr = p.addr
order  by to_number(p.spid)
/
============================
Show a users current sql
Select sql_text
from   v$sqlarea
where  (address, hash_value) in
(select sql_address, sql_hash_value
        from v$session
        where username like '&username')
/
==============================
Session status associated with the specified os process id
select s.username
, s.sid
, s.serial#
, p.spid
, last_call_et
, status
from  V$SESSION s
, V$PROCESS p
where s.PADDR = p.ADDR
and p.spid='&pid'
/
=====================================
All active sql
set feedback off
set serveroutput on size 9999
column username format a20
column sql_text format a55 word_wrapped
begin
  for x in
   (select username||'('||sid||','||serial#||') ospid = '|| process ||
    ' program = ' || program username,
    to_char(LOGON_TIME,' Day HH24:MI') logon_time,
    to_char(sysdate,' Day HH24:MI') current_time,
    sql_address,
    sql_hash_value
   from v$session
   where status = 'ACTIVE'
   and rawtohex(sql_address) <> '00'
   and username is not null ) loop
   for y in (select sql_text
   from v$sqlarea
   where address = x.sql_address ) loop
   if ( y.sql_text not like '%listener.get_cmd%' and
    y.sql_text not like '%RAWTOHEX(SQL_ADDRESS)%' ) then
    dbms_output.put_line( '--------------------' );
    dbms_output.put_line( x.username );
    dbms_output.put_line( x.logon_time || ' ' || x.current_time || ' SQL#=' || x.sql_hash_value);
    dbms_output.put_line( substr( y.sql_text, 1, 250 ) );
   end if;
  end loop;
 end loop;
end;
/
==============================
Display any long operations
set lines 100 pages 999
col username format a15
col message format a40
col remaining format 9999
select username
, to_char(start_time, 'hh24:mi:ss dd/mm/yy') started
, time_remaining remaining
, message
from v$session_longops
where time_remaining = 0
order by time_remaining desc
/
==============================
List open cursors per user
set pages 999
select  sess.username
, sess.sid
, sess.serial#
, stat.value cursors
from v$sesstat stat
, v$statname sn
, v$session sess
where sess.username is not null
and sess.sid = stat.sid
and stat.statistic# = sn.statistic#
and sn.name = 'opened cursors current'
order by value
/
(or)
set lines 100 pages 999
select count(hash_value) cursors
,      sid
,      user_name
from   v$open_cursor
group by
       sid
,      user_name
order by
       cursors
/
======================================