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.
*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 188.8.131.52.0 - 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 = "184.108.40.206.0" 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;