Oracle PL/SQL/System Tables Views/V instance

select Active_State from V$INSTANCE

   
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SQL> select Active_State from V$INSTANCE;
                                                              
ACTIVE_ST
---------
NORMAL
                    
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select Database_Status from V$INSTANCE

   
SQL> select Database_Status from V$INSTANCE;
                                                              
DATABASE_STATUS
-----------------
ACTIVE

v$instance.instance_name

   
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SQL>  select c.value || "/" || d.instance_name ||
  2                     "_ora_" || a.spid || ".trc" trace
  3    from v$process a, v$session b, v$parameter c, v$instance d
  4   where a.addr = b.paddr
  5     and b.audsid = userenv("sessionid")
  6     and c.name = "user_dump_dest"
  7  /
TRACE
--------------------------------------------------------------------------------
C:\ORACLEXE\APP\ORACLE\ADMIN\XE\UDUMP/xe_ora_264.trc
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V$INSTANCE view provides one row of statistics for each Oracle instance running against the database

   
SQL> select instance_name, host_name, version,
  2     startup_time, round(sysdate-startup_time) "Days Up",
  3     status from v$instance;
INSTANCE_NAME
----------------
HOST_NAME
----------------------------------------------------------------
VERSION           STARTUP_T    Days Up STATUS
----------------- --------- ---------- ------------
xe
UBC-1
10.2.0.1.0        26-OCT-09          0 OPEN

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