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Oracle启动过程简析

时间:2021-07-01 10:21:17 帮助过:45人阅读

Oracle数据库启动时,经历了三个过程:(用命名如下)startup nomount;alter database mount; alter database open;当然数据库关

Oracle数据库启动时,经历了三个过程:(用命名如下)
startup nomount;
alter database mount; alter database open;
当然数据库关闭时也是经历了三个相反的过程:
alter database close;
alter database dismount;
shutdown;(shutdown 后面跟了四个参数:normal;immediate;transactional;abort)
四种方式关闭数据库的比较:

(NO YES)

关闭方式 A I T N

允许新的连接 N N N N

等待活动会话终止 N N N Y

等待活动事务终止 N N

  • Y
  • Y

    强制进行checkpoint,关闭所有文件 N Y Y Y

    分析第一个过程startup nomount:
    这个过程数据库首先到参数文件(pfile/spfile)中读取数据库的设置,创建实例.
    数据库所在的操作系统版本:
    [oracle@localhost ~]$ lsb_release -a
    LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch
    Distributor ID: EnterpriseEnterpriseServer
    Description: Enterprise Linux Enterprise Linux Server release 5.5 (Carthage)
    Release: 5.5
    Codename: Carthage

    数据库版本:
    SQL> SELECT * FROM v$version where rownum=1;


    BANNER
    --------------------------------------------------------------------------------
    Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production

    因为spfile是二进制文件,不能直接读取,在linux中,可以用命令String转储出来:
    [oracle@localhost dbs]$ strings spfileorcl3939.ora
    orcl3939.__db_cache_size=54525952
    orcl3939.__java_pool_size=4194304
    orcl3939.__large_pool_size=4194304
    orcl3939.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
    orcl3939.__pga_aggregate_target=171966464
    orcl3939.__sga_target=251658240
    orcl3939.__shared_io_pool_size=0
    orcl3939.__shared_pool_size=176160768
    orcl3939.__streams_pool_size=4194304
    *.audit_file_dest='/u01/app/oracle/admin/orcl3939/adump'
    *.audit_trail='db'
    *.compatible='11.2.0.0.0'
    *.control_files='/u01/app/o
    racle/oradata/orcl3939/control01.ctl','/u01/app/oracle/flash_recovery_area/orcl3939/control02.ctl','/u01/app/oracle/oradata/orcl3939/control03.ctl'
    *.db_block_size=8192
    *.db_domain='localdomain'
    *.db_name='orcl3939'
    *.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
    *.db_recovery_file_dest_size=4039114752
    *.diagnostic_dest='/u01/app/oracle'
    *.dispatchers='(PROTOCOL=TCP) (SERVICE=orcl3939XDB)'
    *.instance_name='ORCL3939'
    *.local_listener='(ADDRESS=(PROTOCOL=TCP)(HOST = local
    host.localdomain)(PORT = 1521))'
    *.memory_target=423624704
    *.open_cursors=300
    *.processes=150
    *.remote_login_passwordfile='EXCLUSIVE'
    *.service_names='a,b,c,d'
    *.trace_enabled=TRUE
    *.undo_tablespace='UNDOTBS1'

    spfile文件中你可以看到数据库在nomount时做了些什么,根据参数文件的内容,创建了instance,分配了相应的内存区域,启动了相应的后台进程。
    我们再看告警日志文件(alert_.log):读取了参数文件,启动了实例

    Starting up:
    Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
    With the Partitioning, OLAP, Data Mining and Real Application Testing options.
    Using parameter settings in server-side spfile /u01/app/oracle/product/11.2.0/dbhome_1/dbs/spfileorcl3939.ora
    System parameters with non-default values:
    processes = 150
    memory_target = 404M
    control_files = "/u01/app/oracle/oradata/orcl3939/control01.ctl"
    control_files = "/u01/app/oracle/flash_recovery_area/orcl3939/control02.ctl"
    control_files = "/u01/app/oracle/oradata/orcl3939/control03.ctl"
    db_block_size = 8192
    compatible = "11.2.0.0.0"
    db_recovery_file_dest = "/u01/app/oracle/flash_recovery_area"
    db_recovery_file_dest_size= 3852M
    undo_tablespace = "UNDOTBS1"
    remote_login_passwordfile= "EXCLUSIVE"
    db_domain = "localdomain"
    instance_name = "ORCL3939"
    service_names = "a,b,c,d"
    dispatchers = "(PROTOCOL=TCP) (SERVICE=orcl3939XDB)"
    local_listener = "(ADDRESS=(PROTOCOL=TCP)(HOST = localhost.localdomain)(PORT = 1521))"
    audit_file_dest = "/u01/app/oracle/admin/orcl3939/adump"
    audit_trail = "DB"
    db_name = "orcl3939"
    open_cursors = 300
    diagnostic_dest = "/u01/app/oracle"
    trace_enabled = TRUE
    Thu Apr 02 14:59:41 2015
    PMON started with pid=2, OS id=5989
    Thu Apr 02 14:59:41 2015
    VKTM started with pid=3, OS id=5991 at elevated priority
    VKTM running at (10)millisec precision with DBRM quantum (100)ms
    Thu Apr 02 14:59:41 2015
    GEN0 started with pid=4, OS id=5995
    Thu Apr 02 14:59:41 2015
    DIAG started with pid=5, OS id=5997
    Thu Apr 02 14:59:41 2015
    DBRM started with pid=6, OS id=5999
    Thu Apr 02 14:59:41 2015
    PSP0 started with pid=7, OS id=6001
    Thu Apr 02 14:59:41 2015
    DIA0 started with pid=8, OS id=6003
    Thu Apr 02 14:59:41 2015
    MMAN started with pid=9, OS id=6005
    Thu Apr 02 14:59:41 2015
    DBW0 started with pid=10, OS id=6007
    Thu Apr 02 14:59:41 2015
    LGWR started with pid=11, OS id=6009
    Thu Apr 02 14:59:41 2015
    CKPT started with pid=12, OS id=6011
    Thu Apr 02 14:59:41 2015
    SMON started with pid=13, OS id=6013
    Thu Apr 02 14:59:41 2015
    RECO started with pid=14, OS id=6015
    Thu Apr 02 14:59:41 2015
    MMON started with pid=15, OS id=6017
    Thu Apr 02 14:59:41 2015
    MMNL started with pid=16, OS id=6019
    starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...
    starting up 1 shared server(s) ...
    ORACLE_BASE from environment = /u01/app/oracle

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