oracle 启动三步骤 -云博客

oracle 启动三步骤

# 数据库 2024-05-05 14:05 0 17 来源：云博客

oracle 启动三步骤

oracle启动会经过三个过程，分别是nomount、mount、open

一、nomount 阶段

nomount 阶段，可以看到实例已经启动。oracle进程会根据参数文件开创共享内存池。

SQL> startup nomount;ORACLE instance started.Total System Global Area 1653518336 bytesFixed Size 2213896 bytesVariable Size 956303352 bytesDatabase Buffers 687865856 bytesRedo Buffers 7135232 bytesSQL>

可以看到共享内存已经开辟

[root@localhost dbs]# ipcs -m------ Shared Memory Segments --------key shmid owner perms bytes nattch status 0x00000000 98304 oracle 600 393216 2 dest 0x00000000 131073 oracle 600 393216 2 dest 0x00000000 163842 oracle 600 393216 2 dest 0x00000000 196611 oracle 600 393216 2 dest 0x00000000 229380 oracle 600 393216 2 dest 0x00000000 262149 oracle 600 393216 2 dest 0x00000000 294918 oracle 600 393216 2 dest 0x00000000 327687 oracle 600 393216 2 dest 0x00000000 360456 oracle 600 393216 2 dest 0x33554094 1048585 oracle 660 4096 0 0x00000000 425994 oracle 600 393216 2 dest 0x00000000 458763 oracle 600 393216 2 dest 0x00000000 491532 oracle 600 393216 2 dest 0x00000000 524301 oracle 600 393216 2 dest 0x00000000 557070 oracle 600 393216 2 dest 0x00000000 688143 oracle 600 393216 2 dest 0x00000000 720912 oracle 600 393216 2 dest

进程已经开启

oracle 2965 1 0 04:44 ? 00:00:00 ora_pmon_testoracle 2967 1 0 04:44 ? 00:00:00 ora_vktm_testoracle 2971 1 0 04:44 ? 00:00:00 ora_gen0_testoracle 2973 1 0 04:44 ? 00:00:00 ora_diag_testoracle 2975 1 0 04:44 ? 00:00:00 ora_dbrm_testoracle 2977 1 0 04:44 ? 00:00:00 ora_psp0_testoracle 2979 1 0 04:44 ? 00:00:00 ora_dia0_testoracle 2981 1 0 04:44 ? 00:00:01 ora_mman_testoracle 2983 1 0 04:44 ? 00:00:00 ora_dbw0_testoracle 2985 1 0 04:44 ? 00:00:00 ora_lgwr_testoracle 2987 1 0 04:44 ? 00:00:00 ora_ckpt_testoracle 2989 1 0 04:44 ? 00:00:00 ora_smon_testoracle 2991 1 0 04:44 ? 00:00:00 ora_reco_testoracle 2993 1 0 04:44 ? 00:00:00 ora_mmon_testoracle 2995 1 0 04:44 ? 00:00:00 ora_mmnl_testoracle 2997 1 0 04:44 ? 00:00:00 ora_d000_testoracle 2999 1 0 04:44 ? 00:00:00 ora_s000_test

查看参数配置文件位置

SQL> show parameter spfileNAME TYPE VALUE------------------------------------ --------------------------------- ------------------------------spfile string /u01/app/oracle/product/11.2.4 /db_1/dbs/spfiletest.oraSQL>

移除配置文件后startup nomount，报错如下：

SQL> startup nomount;ORA-01078: failure in processing system parametersLRM-00109: could not open parameter file ‘/u01/app/oracle/product/11.2.4/db_1/dbs/inittest.ora‘SQL>

二、mount 阶段

mount阶段，oracle会根据nomount阶段的参数文件来寻找控制文件的名称和位置，一旦查找到立即锁定该控制文件，控制文件里记录了数据库中的数据文件、日志文件、检查点信息等非常重要的信息。启动mount时，会先自动启动nomount

startup mount

mount阶段可以看到，比nomount阶段多了一个database mounted的提示。

SQL> startup mount;ORACLE instance started.Total System Global Area 1653518336 bytesFixed Size 2213896 bytesVariable Size 956303352 bytesDatabase Buffers 687865856 bytesRedo Buffers 7135232 bytesDatabase mounted.SQL>

查看控制文件位置

SQL> show parameter controlNAME TYPE VALUE------------------------------------ --------------------------------- ------------------------------control_file_record_keep_time integer 7control_files string /u01/app/oracle/oradata/test/c ontrol01.ctl, /u01/app/oracle/ flash_recovery_area/test/contr ol02.ctlcontrol_management_pack_access string DIAGNOSTIC+TUNINGSQL>

将配置文件移除，然后在启动一次。

SQL> startup mount;ORACLE instance started.Total System Global Area 1653518336 bytesFixed Size 2213896 bytesVariable Size 956303352 bytesDatabase Buffers 687865856 bytesRedo Buffers 7135232 bytesORA-00205: error in identifying control file, check alert log for more infoSQL>

三、open阶段

open阶段会根据控制文件记录的信息，定位到数据库文件、日志文件等，正式开启实例和数据库之间的桥梁。如果数据文件或者日志文件缺少，那么open失败。
open之后，如果有使用归档日志功能，便可看到归档日志的进程。

SQL> alter database open;Database altered.SQL>

查看日志文件和日志文件的位置

SQL> select file_name from dba_data_files;FILE_NAME------------------------------------------------/u01/app/oracle/oradata/test/users01.dbf/u01/app/oracle/oradata/test/undotbs01.dbf/u01/app/oracle/oradata/test/sysaux01.dbf/u01/app/oracle/oradata/test/system01.dbfSQL> SQL> select group#,member from v$logfile; GROUP# MEMBER------------------------------------- 3 /u01/app/oracle/oradata/test/redo03.log 2 /u01/app/oracle/oradata/test/redo02.log 1 /u01/app/oracle/oradata/test/redo01.log

移动一个数据文件后启动，报错如下

SQL> startup;ORACLE instance started.Total System Global Area 1653518336 bytesFixed Size 2213896 bytesVariable Size 956303352 bytesDatabase Buffers 687865856 bytesRedo Buffers 7135232 bytesDatabase mounted.ORA-01157: cannot identify/lock data file 4 - see DBWR trace fileORA-01110: data file 4: ‘/u01/app/oracle/oradata/test/users01.dbf‘SQL>

如果我随便复制一个文件进去可不可以呢？启动如下：

SQL> alter database open;alter database open*ERROR at line 1:ORA-01122: database file 4 failed verification checkORA-01110: data file 4: ‘/u01/app/oracle/oradata/test/users01.dbf‘ORA-01210: data file header is media corrupt