Oracle 12c - Multi threaded Model
SQL> show parameter thread NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ parallel_threads_per_cpu integer 2 thread integer 0 threaded_execution boolean FALSE
Background Processes List
[oracle@kirlinc kiran]$ ps -ef|grep -v grep|grep ora_|awk -F " " '{ print $8 }'|awk 'NR%5!=0{printf "%s ",$0;next}1' ora_pmon_ora12 ora_psp0_ora12 ora_vktm_ora12 ora_gen0_ora12 ora_mman_ora12 ora_diag_ora12 ora_dbrm_ora12 ora_dia0_ora12 ora_dbw0_ora12 ora_lgwr_ora12 ora_ckpt_ora12 ora_smon_ora12 ora_reco_ora12 ora_lreg_ora12 ora_mmon_ora12 ora_mmnl_ora12 ora_d000_ora12 ora_tmon_ora12 ora_tt00_ora12 ora_smco_ora12 ora_w000_ora12 ora_aqpc_ora12 ora_p000_ora12 ora_p001_ora12 ora_p002_ora12 ora_p003_ora12 ora_qm02_ora12 ora_q002_ora12 ora_q003_ora12 ora_cjq0_ora12 ora_w001_ora12 ora_w002_ora12 ora_w003_ora12 ora_w004_ora12 ora_w005_ora12 ora_w006_ora12 ora_w007_ora12 ora_w008_ora12 ora_w009_ora12 ora_s000_ora12 ora_p004_ora12 ora_p005_ora12 ora_p006_ora12 ora_p007_ora12
SQL> alter system set threaded_execution=true scope=spfile; System altered. SQL> startup force ORA-01017: invalid username/password; logon denied
SQL> conn sys as sysdba Enter password: Connected. SQL> show con_name CON_NAME ------------------------------ CDB$ROOT
The previous startup command started only the instances processes, but failed with authentication error when before attempting to mount and open the database. We will need to login with the password to bring up the database
SQL> create user c##admin identified by admin container=all; create user c##admin identified by admin container=all * ERROR at line 1: ORA-01109: database not open SQL> select count(*) from cdb_objects; select count(*) from cdb_objects * ERROR at line 1: ORA-01219: database or pluggable database not open: queries allowed on fixed tables or views only SQL> shutdown abort ORACLE instance shut down. connect using the password.. SQL> conn sys as sysdba Enter password: Connected to an idle instance. SQL> startup ORACLE instance started. Total System Global Area 1653518336 bytes Fixed Size 2289016 bytes Variable Size 989856392 bytes Database Buffers 654311424 bytes Redo Buffers 7061504 bytes Database mounted. Database opened. SQL> select count(*) from cdb_objects; COUNT(*) ---------- 181526 SQL>
[oracle@kirlinc dbs]$ sqlplus SQL*Plus: Release 12.1.0.1.0 Production on Tue Mar 11 17:05:25 2014 Copyright (c) 1982, 2013, Oracle. All rights reserved. Enter user-name: / as sysdba Connected to an idle instance. SQL> startup ORA-01017: invalid username/password; logon denied SQL> shutdown abort ORA-01031: insufficient privileges SQL>
[oracle@kirlinc dbs]$ orapwd file=orapwora12 password=sys1234 SQL> conn sys/sys1234 as sysdba Connected. SQL> startup force ORACLE instance started. Total System Global Area 1653518336 bytes Fixed Size 2289016 bytes Variable Size 989856392 bytes Database Buffers 654311424 bytes Redo Buffers 7061504 bytes Database mounted. Database opened. SQL>
==> Database with the new mode has been started..let's check the back ground processes now.
[kiran@kirlinc ~]$ pidstat|grep ora_|awk -F " " '{ print $9 }'|awk 'NR%5!=0{printf "%s ",$0;next}1' ora_pmon_ora12 ora_psp0_ora12 ora_vktm_ora12 ora_scmn_ora12 ora_scmn_ora12 ora_dbw0_ora12 [kiran@kirlinc ~]$
As you see there are only 5 of the thread processes running for the whole database. You can query v$process view to find more information about the running thread processes.
SQL> select count(*),execution_type from v$process group by execution_type; COUNT(*) EXECUTION_ ---------- ---------- 4 PROCESS 1 NONE 35 THREAD SQL> select program from v$process where execution_type='PROCESS'; PROGRAM ------------------------------------------------ oracle'@'kirlinc.home (PMON) oracle'@'kirlinc.home (PSP0) oracle'@'kirlinc.home (VKTM) oracle'@'kirlinc.home (DBW0)
rajkiran

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datetime: 2000-01-01 00:00:00
date: 2018-02-01
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