1，oracle启动过程
nomount(instance started) -> mount(database mounted) -> open(database opened)
SQL> startup
ORACLE instance started.
Total System Global Area 599785472 bytes
Fixed Size 2022632 bytes
Variable Size 121635608 bytes
Database Buffers 473956352 bytes
Redo Buffers 2170880 bytes
Database mounted.
Database opened. 启动数据库的后台日志：
Thu Nov 8 20:01:04 2012
Starting ORACLE instance (normal) --start instance
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Picked latch-free SCN scheme 1
Using LOG_ARCHIVE_DEST_10 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 disabled
ksdpec: called for event 13740 prior to event group initialization
Starting up ORACLE RDBMS Version: 10.2.0.1.0.
System parameters with non-default values:
processes = 150
__shared_pool_size = 163577856
__large_pool_size = 4194304
__java_pool_size = 4194304
__streams_pool_size = 0
nls_date_language = american
nls_date_format = yyyy-mm-dd
nls_timestamp_format = yyyy-mm-dd hh24:mi:ss
sga_target = 599785472
control_files = /home/oracle/oracle/oradata/TESTDB/control01.ctl,
/home/oracle/oracle/oradata/TESTDB/control02.ctl,
/home/oracle/oracle/oradata/TESTDB/control03.ctl
db_block_size = 8192
__db_cache_size = 423624704
compatible = 10.2.0.1.0
db_file_multiblock_read_count= 16
db_recovery_file_dest = /home/oracle/oracle/flash_recovery_area
db_recovery_file_dest_size= 2147483648
undo_management = AUTO
undo_tablespace = UNDOTBS1
remote_login_passwordfile= EXCLUSIVE
db_domain =
dispatchers = (PROTOCOL=TCP) (SERVICE=LCDMP2XDB)
job_queue_processes = 10
background_dump_dest = /home/oracle/oracle/admin/TESTDB/bdump
user_dump_dest = /home/oracle/oracle/admin/TESTDB/udump
core_dump_dest = /home/oracle/oracle/admin/TESTDB/cdump
audit_file_dest = /home/oracle/oracle/admin/TESTDB/adump
db_name = TESTDB
open_cursors = 300
pga_aggregate_target = 199229440
PMON started with pid=2, OS id=22564
PSP0 started with pid=3, OS id=22566
MMAN started with pid=4, OS id=22568
DBW0 started with pid=5, OS id=22570
LGWR started with pid=6, OS id=22572
CKPT started with pid=7, OS id=22574
SMON started with pid=8, OS id=22576
RECO started with pid=9, OS id=22578
CJQ0 started with pid=10, OS id=22580
MMON started with pid=11, OS id=22582
MMNL started with pid=12, OS id=22584
Thu Nov 8 20:01:04 2012
starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...
starting up 1 shared server(s) ...
Thu Nov 8 20:01:04 2012
ALTER DATABASE MOUNT --mount
Thu Nov 8 20:01:08 2012
Setting recovery target incarnation to 2
Thu Nov 8 20:01:08 2012
Successful mount of redo thread 1, with mount id 1508843648
Thu Nov 8 20:01:08 2012
Database mounted in Exclusive Mode
Completed: ALTER DATABASE MOUNT --mount over
Thu Nov 8 20:01:09 2012
ALTER DATABASE OPEN --db open
Thu Nov 8 20:01:09 2012
Thread 1 opened at log sequence 3442
Current log# 1 seq# 3442 mem# 0: /home/oracle/oracle/oradata/TESTDB/redo01.log
Successful open of redo thread 1
Thu Nov 8 20:01:09 2012
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Thu Nov 8 20:01:09 2012
SMON: enabling cache recovery
Thu Nov 8 20:01:09 2012
Successfully onlined Undo Tablespace 1.
Thu Nov 8 20:01:09 2012
SMON: enabling tx recovery
Thu Nov 8 20:01:09 2012
Database Characterset is AL32UTF8
replication_dependency_tracking turned off (no async multimaster replication found)
Starting background process QMNC
QMNC started with pid=17, OS id=22594
Thu Nov 8 20:01:10 2012
db_recovery_file_dest_size of 2048 MB is 0.00% used. This is a
user-specified limit on the amount of space that will be used by this
database for recovery-related files, and does not reflect the amount of
space available in the underlying filesystem or ASM diskgroup.
Thu Nov 8 20:01:11 2012
Completed: ALTER DATABASE OPEN --db open overinstance started （启动数据库实例）：
既然是启动实例，那么oracle首先根据参数文件参数创建实例，分配内存，启动后台进程。
进程信息中pid表示进程在数据库内部的标识符号，os id表示进程在操作系统上的进程编号
PMON started with pid=2, OS id=22564
[oracle@oracle ~]$ ps -ef|grep 22564
oracle 2530 2504 0 11:46 pts/1 00:00:00 grep 22564
oracle 22564 1 0 Nov08 ? 00:00:00 ora_pmon_TESTDB
2，oracle关闭过程
与启动过程正好相反，为逆向过程
database closed -> database dismounted -> instance shut down
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down. 关闭数据库的后台日志：
Thu Nov 8 19:54:47 2012
Starting background process EMN0
EMN0 started with pid=25, OS id=22441
Thu Nov 8 19:54:47 2012
Shutting down instance: further logons disabled
Thu Nov 8 19:54:48 2012
Stopping background process CJQ0
Thu Nov 8 19:54:48 2012
Stopping background process QMNC
Thu Nov 8 19:54:50 2012
Stopping background process MMNL
Thu Nov 8 19:54:51 2012
Stopping background process MMON
Thu Nov 8 19:54:52 2012
Shutting down instance (immediate)
License high water mark = 9
Thu Nov 8 19:54:52 2012
Stopping Job queue slave processes
Thu Nov 8 19:54:57 2012
Process OS id : 22429 alive after kill
Errors in file
Thu Nov 8 19:54:57 2012
Job queue slave processes stopped
All dispatchers and shared servers shutdown
Thu Nov 8 19:55:09 2012
PMON failed to acquire latch, see PMON dump
Thu Nov 8 19:55:10 2012
ALTER DATABASE CLOSE NORMAL
Thu Nov 8 19:55:10 2012
SMON: disabling tx recovery
SMON: disabling cache recovery
Thu Nov 8 19:55:10 2012
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
Thread 1 closed at log sequence 3442
Successful close of redo thread 1
Thu Nov 8 19:55:10 2012
Completed: ALTER DATABASE CLOSE NORMAL
Thu Nov 8 19:55:10 2012
ALTER DATABASE DISMOUNT
Completed: ALTER DATABASE DISMOUNT
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active