today I got a question from Oracle dba group which background process will start first when the instance is started? (When considering in oracle 10g)

Many of them gave the answer is "smon" but it was the wrong answer one of the group members answered psp0 (PROCESS SPAWNER) then I searched on google about PSP process and here we can see about PSP(PROCESS SPAWNER) process.

PSP0:

*This process spawner process is responsible for creating and managing other Oracle processes.

*The first process that will be started when we started the instance "This process is called PROCESS SPAWNER".

*It was introduced in Oracle 10g

When Considering in Oracle 11g:

*After started the instance the first process has been started Pmon and PSP0 here We can check the alert log file

My database name is "Dhoni"



SQL> shut immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

 

At the time of checking alert log file:


Shutting down instance (immediate)
Stopping background process SMCO
Shutting down instance: further logons disabled
Fri Aug 18 14:48:00 2017
Stopping background process CJQ0
Stopping background process QMNC
Stopping background process MMNL
Stopping background process MMON
License high water mark = 3
All dispatchers and shared servers shutdown
ALTER DATABASE CLOSE NORMAL
Fri Aug 18 14:48:03 2017
SMON: disabling tx recovery
SMON: disabling cache recovery
Fri Aug 18 14:48:06 2017
Shutting down archive processes
Archiving is disabled
Fri Aug 18 14:48:06 2017
ARCH shutting down
ARC3: Archival stopped
Fri Aug 18 14:48:06 2017
ARCH shutting down
Fri Aug 18 14:48:06 2017
ARCH shutting down
ARC1: Archival stopped
ARC2: Archival stopped
Fri Aug 18 14:48:06 2017
ARCH shutting down
ARC0: Archival stopped
Thread 1 closed at log sequence 136
Successful close of redo thread 1
Fri Aug 18 14:48:11 2017
Completed: ALTER DATABASE CLOSE NORMAL
ALTER DATABASE DISMOUNT
Completed: ALTER DATABASE DISMOUNT
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
Fri Aug 18 14:48:16 2017
Stopping background process VKTM
Fri Aug 18 14:48:19 2017
Instance shutdown complete

 

The next step are we would start our database


Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Picked latch-free SCN scheme 2
Using LOG_ARCHIVE_DEST_1 parameter default value as USE_DB_RECOVERY_FILE_DEST
Autotune of undo retention is turned on. 
IMODE=BR
ILAT =18
LICENSE_MAX_USERS = 0
SYS auditing is enabled
Starting up:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - Production.
Using parameter settings in server-side spfile C:\ORACLEXE\APP\ORACLE\PRODUCT\11.2.0\SERVER\DATABASE\SPFILEXE.ORA
System parameters with non-default values:
  sessions                 = 172
  resource_limit           = TRUE
  memory_target            = 520M
  control_files            = "C:\ORACLEXE\CONTROL01.DBF"
  control_files            = "C:\ORACLEXE\APP\ORACLE\ORADATA\XE\CONTROL.DBF"
  compatible               = "11.2.0.0.0"
  log_archive_dest         = "C:\oraclexe\app\oracle\fast_recovery_area\XE\arch"
  db_recovery_file_dest    = "C:\oraclexe\app\oracle\fast_recovery_area"
  db_recovery_file_dest_size= 10G
  undo_management          = "AUTO"
  undo_tablespace          = "UNDOTBS1"
  undo_retention           = 1500
  remote_login_passwordfile= "EXCLUSIVE"
  audit_sys_operations     = TRUE
  dispatchers              = "(PROTOCOL=TCP) (SERVICE=XEXDB)"
  shared_servers           = 4
  plsql_optimize_level     = 3
  audit_file_dest          = "C:\ORACLEXE\APP\ORACLE\ADMIN\XE\ADUMP"
  audit_trail              = "DB"
  sort_area_size           = 5
  db_name                  = "DHONI"
  open_cursors             = 300
  ddl_lock_timeout         = 600
  parallel_servers_target  = 0
  diagnostic_dest          = "C:\ORACLEXE\APP\ORACLE"

Note:It's verifying the spfile anmd parameters

 

The first Process started in database of oracle 11g





Fri Aug 18 14:57:49 2017
PMON started with pid=2, OS id=7352 
Fri Aug 18 14:57:49 2017
PSP0 started with pid=3, OS id=4840 

To views the process in query


  

   SQL> select pid,spid,pname from V$process;

  

 

source: pavandba,oracle