当今时代
技术人员，真正的差距其实在意识
1.忽略了知识的重点
20%的知识，解决80%的问题
2.从未考虑知识落地
知识要落地， 要思考应用的场合。
学习任何技术都是一样的，没有思考过你所学的某项技术有什么用，没有想过如何落地，如何应用到实际工作中去，都是毫无意义的学习，纯属浪费生命。
3.选择技术使用场景
1.该如何请教他人
2.问题该怎样描述
3.失误不只是粗心，
准确地把握需求，尽可能少做事！不要小看这句话，这是一句永不过时的化。——少做事。
保证精简学习的内容，要最快地掌握。将学习和工作结合在一起，带着知识点该如何落地应用以及什么时候该选择什么技术的想法去学习。这样目的性极强的探索性质的学习，往往学习一遍就够了。
强调知识的落地，探讨最多的话题就是，学习这些知识有什么用，
第一章意识，少做事从学习开始
学什么先了解要做什么
数据库应用可用分为：
- 数据库开发： SQL语句的增删改查，PL/SQL逻辑处理
- 数据库管理：安装、部署、调参、备份恢复、数据迁移、分配用户、权限管控、表空间划分、故障定位、问题分析、数据库诊断修复
- 数据库优化：解决性能问题，提升数据库运行效率
- 数据库设计：深入了解需求业务和数据库原理，数据库模型建设、数据库对象的设计（表、索引）
第二章 震惊，体验物理体系之旅
Oracle体系结构图
一、Oracle由实例和数据库组成
二、实例由一个共享内存区SGA(System Global Area)和一系列后台进程组成的，其中SGA主要被划分为共享池（shared pool）、数据缓存区（db cache）和日志缓存区（log buffer）三类。后台进程包括PMON,SMON,LCKn,RECO,CKPT,DBWR,LGWR,ARCH等系列进程。
三、数据库是由数据文件、参数文件、日志文件、控制文件、归档日志文件等一系列文件组成的，其中归档日志最终可能会被转移到新的存储介质中，用于备份恢复使用。
四、PGA（Program Global Area）区，和SGA明显区别在于，PGA不是共享内存，是私有不共享的，用户对数据库发起的无论查询还是更新的任何操作，都先在PGA进行预处理，然后才进入实例区域，由SGA和后台进程共同完成。
PGA的具体作用：
第一，保护用户的连接信息。会话属性、绑定变量
第二，保护用户权限等重要信息，
第三，当发起的指令需要排序时，PGA中可进行排序。
查看回滚段的相关参数
undo_management 为AUTO表示自动进行回滚段管理，回滚段空间不够时候可以自动扩展
undo_retention 为 900, DML语句需要记录前镜像，当COMMIT后，表示回滚段保留的前镜像被打上了可以覆盖重新使用的标记。但是要在900秒后方可允许。
undo_tablespace 为UNDOTBS1，表示回滚段表空间的名字为UNDOTBS1
SQL> show parameter undo
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
temp_undo_enabled boolean FALSE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
SQL> 查看SGA及PGA的大小分配
SQL> show user
USER is "SYS"
SQL> show parameter sga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
allow_group_access_to_sga boolean FALSE
lock_sga boolean FALSE
pre_page_sga boolean TRUE
sga_max_size big integer 600M
sga_min_size big integer 0
sga_target big integer 0
unified_audit_sga_queue_size integer 1048576
SQL> show parameter pga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
pga_aggregate_limit big integer 2G
pga_aggregate_target big integer 200M
SQL> 查看共享池和数据缓存区的大小分配
SQL>
SQL> show user;
USER is "SYS"
SQL> show parameter shared_pool_size
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
shared_pool_size big integer 0
SQL> show parameter db_cache_size
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
db_cache_size big integer 0
SQL> 使用ipcs-m 查看共享内存的命令
[oracle@oracle-db-19c ~]$ ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 0 oracle 600 9138176 128
0x00000000 1 oracle 600 612368384 64
0x00000000 2 oracle 600 7639040 64
0x8239f754 3 oracle 600 16384 64
0x00000000 8 oracle 600 524288 2 dest
[oracle@oracle-db-19c ~]$ 查看日志缓存区的大小
SQL>
SQL> show user;
USER is "SYS"
SQL> show parameter log_buffer
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
log_buffer big integer 7136K
SQL> 参数的设置如何修改？
alter system命令增加了一个新的选项scope。scope参数有3个可选值：memory、spfile和both.
- memory :只改变当前实例运行，重新启动数据库后失效。
- spfile:只改变spfile的设置，不改变当前实例运行，重新启动数据库后生效
- both：同时改变实例及spfile，当前更改立即生效，重新启动数据库后仍然有效。
可以通过alter system或导入导出来更改spfile的内容
针对RAC环境，alter system还可以指定sid参数，对不同实例进行不同的设置。
通过spfile修改参数的完整命令如下：
alter system set <parameter_name>=<value> scope=memory|spfile|both[sid=<sid_name>]- 如果当前实例使用的pfile而非spfile，则scope=spfile或scope=both会产生错误
- 如果实例以pfile启动，则scope的默认值为memory,若以spfile启动，则默认值为both.
- 有些参数必须重启才能生效，如log_buffer.
- scope的默认值为both
修改SGA的大小（scope=spfile的方式）
SQL> set pagesize 200
SQL> set linesize 200
SQL>
SQL> show parameter sga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
allow_group_access_to_sga boolean FALSE
lock_sga boolean FALSE
pre_page_sga boolean TRUE
sga_max_size big integer 600M
sga_min_size big integer 0
sga_target big integer 0
unified_audit_sga_queue_size integer 1048576
SQL>
SQL> show user
USER is "SYS"
SQL>
SQL> alter system set sga_target=500M scope=spfile;
System altered.
SQL> show parameter sga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
allow_group_access_to_sga boolean FALSE
lock_sga boolean FALSE
pre_page_sga boolean TRUE
sga_max_size big integer 600M
sga_min_size big integer 0
sga_target big integer 0
unified_audit_sga_queue_size integer 1048576
SQL>
SQL>
SQL> show user
USER is "SYS"
SQL> show parameter sga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
allow_group_access_to_sga boolean FALSE
lock_sga boolean FALSE
pre_page_sga boolean TRUE
sga_max_size big integer 600M
sga_min_size big integer 0
sga_target big integer 0
unified_audit_sga_queue_size integer 1048576
SQL> alter system set sga_target=600M scope=both;
System altered.
SQL> show parameter sga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
allow_group_access_to_sga boolean FALSE
lock_sga boolean FALSE
pre_page_sga boolean TRUE
sga_max_size big integer 600M
sga_min_size big integer 0
sga_target big integer 600M
unified_audit_sga_queue_size integer 1048576
SQL> log_buffer等参数修改后必须重启才能生效。（需要重启之后才能生效）
[oracle@oracle-db-19c ~]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jan 2 21:30:22 2023
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
SQL> show user
USER is "SYS"
SQL> show con_name;
CON_NAME
------------------------------
CDB$ROOT
SQL> show parameter log_buffer;
NAME TYPE
------------------------------------ ---------------------------------
VALUE
------------------------------
log_buffer big integer
7136K
SQL> set pagesize 200
SQL> set linesize 200
SQL> show parameter log_buffer;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
log_buffer big integer 7136K
SQL> alter system set log_buffer=15000K scope=memory;
alter system set log_buffer=15000K scope=memory
*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified
SQL> alter system set log_buffer=15000K scope=both;
alter system set log_buffer=15000K scope=both
*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified
SQL> alter system set log_buffer=15000K scope=spfile;
System altered.
SQL> show parameter log_buffer;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
log_buffer big integer 7136K
SQL>
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL> startup
ORACLE instance started.
Total System Global Area 629145392 bytes
Fixed Size 9137968 bytes
Variable Size 197132288 bytes
Database Buffers 406847488 bytes
Redo Buffers 16027648 bytes
Database mounted.
Database opened.
SQL>
SQL> show user;
USER is "SYS"
SQL> show parameter log_buffer;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
log_buffer big integer 15000K
SQL> 进程的体会
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ ps -ef | grep oracle
avahi 997 1 0 Jan01 ? 00:00:02 avahi-daemon: running [oracle-db-19c.local]
oracle 1728 1 0 Jan01 ? 00:00:01 /u01/app/oracle/product/19.3.0/dbhome_1/bin/tnslsnr LISTENER -inherit
oracle 2320 1 0 Jan01 ? 00:00:00 /usr/lib/systemd/systemd --user
oracle 2325 2320 0 Jan01 ? 00:00:00 (sd-pam)
oracle 2340 2320 0 Jan01 ? 00:00:00 /usr/bin/pulseaudio --daemonize=no --log-target=journal
oracle 2349 1 0 Jan01 ? 00:00:00 /usr/bin/gnome-keyring-daemon --daemonize --login
oracle 2355 2286 0 Jan01 tty2 00:00:00 /usr/libexec/gdm-wayland-session --register-session gnome-session
oracle 2357 2320 0 Jan01 ? 00:00:00 /usr/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
oracle 2360 2355 0 Jan01 tty2 00:00:00 /usr/libexec/gnome-session-binary
oracle 2471 2360 0 Jan01 tty2 00:01:00 /usr/bin/gnome-shell
oracle 2516 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfsd
oracle 2523 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfsd-fuse /run/user/1501/gvfs -f -o big_writes
oracle 2526 2471 0 Jan01 tty2 00:00:00 /usr/bin/Xwayland :0 -rootless -terminate -accessx -core -auth /run/user/1501/.mutter-Xwaylandauth.1Q8PW1 -listen 4 -listen 5 -displayfd 6
oracle 2535 2320 0 Jan01 ? 00:00:00 /usr/libexec/at-spi-bus-launcher
oracle 2540 2535 0 Jan01 ? 00:00:00 /usr/bin/dbus-daemon --config-file=/usr/share/defaults/at-spi2/accessibility.conf --nofork --print-address 3
oracle 2547 2320 0 Jan01 ? 00:00:00 /usr/libexec/at-spi2-registryd --use-gnome-session
oracle 2554 2471 0 Jan01 tty2 00:00:02 ibus-daemon --xim --panel disable
oracle 2558 2554 0 Jan01 tty2 00:00:00 /usr/libexec/ibus-dconf
oracle 2560 2554 0 Jan01 tty2 00:00:00 /usr/libexec/ibus-extension-gtk3
oracle 2562 2320 0 Jan01 ? 00:00:00 /usr/libexec/xdg-permission-store
oracle 2567 1 0 Jan01 tty2 00:00:00 /usr/libexec/ibus-x11 --kill-daemon
oracle 2571 2320 0 Jan01 ? 00:00:00 /usr/libexec/ibus-portal
oracle 2573 2320 0 Jan01 ? 00:00:00 /usr/libexec/gnome-shell-calendar-server
oracle 2592 2320 0 Jan01 ? 00:00:00 /usr/libexec/dconf-service
oracle 2598 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfs-udisks2-volume-monitor
oracle 2607 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfs-mtp-volume-monitor
oracle 2611 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfs-gphoto2-volume-monitor
oracle 2615 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfs-afc-volume-monitor
oracle 2620 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfs-goa-volume-monitor
oracle 2624 2320 0 Jan01 ? 00:00:00 /usr/libexec/goa-daemon
oracle 2628 2320 0 Jan01 ? 00:00:00 /usr/libexec/evolution-source-registry
oracle 2653 2320 0 Jan01 ? 00:00:11 /usr/libexec/goa-identity-service
oracle 2664 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-power
oracle 2665 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-print-notifications
oracle 2668 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-rfkill
oracle 2670 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-screensaver-proxy
oracle 2678 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-sharing
oracle 2691 2360 0 Jan01 tty2 00:00:05 /usr/libexec/gsd-smartcard
oracle 2692 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-sound
oracle 2694 2320 0 Jan01 ? 00:00:00 /usr/libexec/evolution-calendar-factory
oracle 2696 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-xsettings
oracle 2713 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-wacom
oracle 2714 2554 0 Jan01 tty2 00:00:00 /usr/libexec/ibus-engine-simple
oracle 2728 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-account
oracle 2733 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-a11y-settings
oracle 2738 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-color
oracle 2743 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-clipboard
oracle 2749 2360 0 Jan01 tty2 00:00:04 /usr/libexec/gsd-housekeeping
oracle 2750 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-datetime
oracle 2754 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-media-keys
oracle 2759 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-keyboard
oracle 2761 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-mouse
oracle 2805 2360 0 Jan01 tty2 00:00:19 /usr/bin/gnome-software --gapplication-service
oracle 2827 2694 0 Jan01 ? 00:00:00 /usr/libexec/evolution-calendar-factory-subprocess --factory all --bus-name org.gnome.evolution.dataserver.Subprocess.Backend.Calendarx2694x2 --own-path /org/gnome/evolution/dataserver/Subprocess/Backend/Calendar/2694/2
oracle 2836 1 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-printer
oracle 2838 1 0 Jan01 tty2 00:03:07 /usr/bin/vmtoolsd -n vmusr --blockFd 3 --uinputFd 4
oracle 2847 2360 0 Jan01 tty2 00:00:00 /usr/libexec/tracker-miner-apps
oracle 2859 2360 0 Jan01 tty2 00:00:00 /usr/libexec/tracker-miner-fs
oracle 2872 2320 0 Jan01 ? 00:00:00 /usr/libexec/evolution-addressbook-factory
oracle 2885 2360 0 Jan01 tty2 00:00:00 /usr/libexec/gsd-disk-utility-notify
oracle 2892 2320 0 Jan01 ? 00:00:00 /usr/libexec/tracker-store
oracle 2941 2872 0 Jan01 ? 00:00:00 /usr/libexec/evolution-addressbook-factory-subprocess --factory all --bus-name org.gnome.evolution.dataserver.Subprocess.Backend.AddressBookx2872x2 --own-path /org/gnome/evolution/dataserver/Subprocess/Backend/AddressBook/2872/2
oracle 3118 2320 0 Jan01 ? 00:00:00 /usr/libexec/gvfsd-metadata
root 113173 113110 0 20:20 pts/0 00:00:00 su - oracle
oracle 113174 113173 0 20:20 pts/0 00:00:00 -bash
oracle 113221 113174 0 20:20 pts/0 00:00:00 rlwrap sqlplus / as sysdba
oracle 113222 113221 0 20:20 pts/1 00:00:00 sqlplus as sysdba
root 114023 113977 0 20:32 pts/2 00:00:00 su - oracle
oracle 114024 114023 0 20:32 pts/2 00:00:00 -bash
root 116914 116791 0 21:21 pts/3 00:00:00 su - oracle
oracle 116915 116914 0 21:21 pts/3 00:00:00 -bash
oracle 117683 116915 0 21:30 pts/3 00:00:00 rlwrap sqlplus / as sysdba
oracle 117684 117683 0 21:30 pts/5 00:00:00 sqlplus as sysdba
oracle 117952 1 0 21:33 ? 00:00:00 ora_pmon_cdb1
oracle 117954 1 0 21:33 ? 00:00:00 ora_clmn_cdb1
oracle 117956 1 0 21:33 ? 00:00:00 ora_psp0_cdb1
oracle 117958 1 0 21:33 ? 00:00:00 ora_vktm_cdb1
oracle 117962 1 0 21:33 ? 00:00:00 ora_gen0_cdb1
oracle 117964 1 0 21:33 ? 00:00:00 ora_mman_cdb1
oracle 117968 1 0 21:33 ? 00:00:00 ora_gen1_cdb1
oracle 117971 1 0 21:33 ? 00:00:00 ora_diag_cdb1
oracle 117973 1 0 21:33 ? 00:00:00 ora_ofsd_cdb1
oracle 117976 1 0 21:33 ? 00:00:00 ora_dbrm_cdb1
oracle 117978 1 0 21:33 ? 00:00:00 ora_vkrm_cdb1
oracle 117980 1 0 21:33 ? 00:00:00 ora_svcb_cdb1
oracle 117982 1 0 21:33 ? 00:00:00 ora_pman_cdb1
oracle 117984 1 0 21:33 ? 00:00:00 ora_dia0_cdb1
oracle 117986 1 0 21:33 ? 00:00:00 ora_dbw0_cdb1
oracle 117988 1 0 21:33 ? 00:00:00 ora_lgwr_cdb1
oracle 117990 1 0 21:33 ? 00:00:00 ora_ckpt_cdb1
oracle 117992 1 0 21:33 ? 00:00:00 ora_lg00_cdb1
oracle 117994 1 0 21:33 ? 00:00:00 ora_smon_cdb1
oracle 117996 1 0 21:33 ? 00:00:00 ora_lg01_cdb1
oracle 117998 1 0 21:33 ? 00:00:00 ora_smco_cdb1
oracle 118000 1 0 21:33 ? 00:00:00 ora_reco_cdb1
oracle 118002 1 0 21:33 ? 00:00:00 ora_w000_cdb1
oracle 118004 1 0 21:33 ? 00:00:00 ora_lreg_cdb1
oracle 118006 1 0 21:33 ? 00:00:00 ora_w001_cdb1
oracle 118008 1 0 21:33 ? 00:00:00 ora_pxmn_cdb1
oracle 118012 1 1 21:33 ? 00:00:03 ora_mmon_cdb1
oracle 118014 1 0 21:33 ? 00:00:00 ora_mmnl_cdb1
oracle 118016 1 0 21:33 ? 00:00:00 ora_d000_cdb1
oracle 118018 1 0 21:33 ? 00:00:00 ora_s000_cdb1
oracle 118020 1 0 21:33 ? 00:00:00 ora_tmon_cdb1
oracle 118023 1 0 21:33 ? 00:00:00 ora_m000_cdb1
oracle 118029 117684 2 21:33 ? 00:00:05 oraclecdb1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 118031 1 0 21:33 ? 00:00:00 ora_tt00_cdb1
oracle 118033 1 0 21:33 ? 00:00:00 ora_tt01_cdb1
oracle 118035 1 0 21:33 ? 00:00:00 ora_tt02_cdb1
oracle 118060 1 0 21:33 ? 00:00:00 ora_w002_cdb1
oracle 118062 1 0 21:33 ? 00:00:00 ora_aqpc_cdb1
oracle 118071 1 0 21:33 ? 00:00:00 ora_p000_cdb1
oracle 118073 1 0 21:33 ? 00:00:00 ora_p001_cdb1
oracle 118075 1 0 21:33 ? 00:00:00 ora_p002_cdb1
oracle 118077 1 0 21:33 ? 00:00:00 ora_p003_cdb1
oracle 118079 1 0 21:33 ? 00:00:00 ora_p004_cdb1
oracle 118081 1 0 21:33 ? 00:00:00 ora_p005_cdb1
oracle 118083 1 0 21:33 ? 00:00:00 ora_p006_cdb1
oracle 118085 1 0 21:33 ? 00:00:00 ora_p007_cdb1
oracle 118087 1 0 21:33 ? 00:00:00 ora_w003_cdb1
oracle 118096 1 0 21:34 ? 00:00:00 ora_w004_cdb1
oracle 118102 1 0 21:34 ? 00:00:00 ora_qm02_cdb1
oracle 118106 1 1 21:34 ? 00:00:01 ora_q002_cdb1
oracle 118108 1 0 21:34 ? 00:00:00 ora_q003_cdb1
oracle 118290 1 0 21:34 ? 00:00:00 ora_m001_cdb1
oracle 118292 1 0 21:34 ? 00:00:01 ora_m002_cdb1
oracle 118294 1 0 21:34 ? 00:00:00 ora_m003_cdb1
oracle 118314 1 0 21:34 ? 00:00:01 ora_cjq0_cdb1
oracle 118322 1 0 21:34 ? 00:00:00 ora_p008_cdb1
oracle 118324 1 0 21:34 ? 00:00:00 ora_p009_cdb1
oracle 118326 1 0 21:34 ? 00:00:00 ora_p00a_cdb1
oracle 118328 1 0 21:34 ? 00:00:00 ora_p00b_cdb1
root 118369 116863 0 21:37 pts/4 00:00:00 su - oracle
oracle 118370 118369 0 21:37 pts/4 00:00:00 -bash
oracle 118429 118370 0 21:37 pts/4 00:00:00 ps -ef
oracle 118430 118370 0 21:37 pts/4 00:00:00 grep --color=auto oracle
[oracle@oracle-db-19c ~]$ 查看Oracle实例名
SQL>
SQL> show user
USER is "SYS"
SQL> show parameter instance_name
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
instance_name string cdb1
SQL> 为了能够更加准确的进行搜索，改用以下方式：
[oracle@oracle-db-19c ~]$ ps -ef | grep cdb1
oracle 117952 1 0 21:33 ? 00:00:00 ora_pmon_cdb1
oracle 117954 1 0 21:33 ? 00:00:00 ora_clmn_cdb1
oracle 117956 1 0 21:33 ? 00:00:00 ora_psp0_cdb1
oracle 117958 1 0 21:33 ? 00:00:02 ora_vktm_cdb1
oracle 117962 1 0 21:33 ? 00:00:00 ora_gen0_cdb1
oracle 117964 1 0 21:33 ? 00:00:00 ora_mman_cdb1
oracle 117968 1 0 21:33 ? 00:00:00 ora_gen1_cdb1
oracle 117971 1 0 21:33 ? 00:00:00 ora_diag_cdb1
oracle 117973 1 0 21:33 ? 00:00:00 ora_ofsd_cdb1
oracle 117976 1 0 21:33 ? 00:00:00 ora_dbrm_cdb1
oracle 117978 1 0 21:33 ? 00:00:00 ora_vkrm_cdb1
oracle 117980 1 0 21:33 ? 00:00:00 ora_svcb_cdb1
oracle 117982 1 0 21:33 ? 00:00:00 ora_pman_cdb1
oracle 117984 1 0 21:33 ? 00:00:00 ora_dia0_cdb1
oracle 117986 1 0 21:33 ? 00:00:00 ora_dbw0_cdb1
oracle 117988 1 0 21:33 ? 00:00:00 ora_lgwr_cdb1
oracle 117990 1 0 21:33 ? 00:00:00 ora_ckpt_cdb1
oracle 117992 1 0 21:33 ? 00:00:00 ora_lg00_cdb1
oracle 117994 1 0 21:33 ? 00:00:00 ora_smon_cdb1
oracle 117996 1 0 21:33 ? 00:00:00 ora_lg01_cdb1
oracle 117998 1 0 21:33 ? 00:00:00 ora_smco_cdb1
oracle 118000 1 0 21:33 ? 00:00:00 ora_reco_cdb1
oracle 118002 1 0 21:33 ? 00:00:00 ora_w000_cdb1
oracle 118004 1 0 21:33 ? 00:00:00 ora_lreg_cdb1
oracle 118006 1 0 21:33 ? 00:00:00 ora_w001_cdb1
oracle 118008 1 0 21:33 ? 00:00:00 ora_pxmn_cdb1
oracle 118012 1 1 21:33 ? 00:00:04 ora_mmon_cdb1
oracle 118014 1 0 21:33 ? 00:00:00 ora_mmnl_cdb1
oracle 118016 1 0 21:33 ? 00:00:00 ora_d000_cdb1
oracle 118018 1 0 21:33 ? 00:00:00 ora_s000_cdb1
oracle 118020 1 0 21:33 ? 00:00:00 ora_tmon_cdb1
oracle 118023 1 0 21:33 ? 00:00:00 ora_m000_cdb1
oracle 118029 117684 1 21:33 ? 00:00:05 oraclecdb1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 118031 1 0 21:33 ? 00:00:00 ora_tt00_cdb1
oracle 118033 1 0 21:33 ? 00:00:00 ora_tt01_cdb1
oracle 118035 1 0 21:33 ? 00:00:00 ora_tt02_cdb1
oracle 118060 1 0 21:33 ? 00:00:00 ora_w002_cdb1
oracle 118062 1 0 21:33 ? 00:00:00 ora_aqpc_cdb1
oracle 118071 1 0 21:33 ? 00:00:00 ora_p000_cdb1
oracle 118073 1 0 21:33 ? 00:00:00 ora_p001_cdb1
oracle 118075 1 0 21:33 ? 00:00:00 ora_p002_cdb1
oracle 118077 1 0 21:33 ? 00:00:00 ora_p003_cdb1
oracle 118079 1 0 21:33 ? 00:00:00 ora_p004_cdb1
oracle 118081 1 0 21:33 ? 00:00:00 ora_p005_cdb1
oracle 118083 1 0 21:33 ? 00:00:00 ora_p006_cdb1
oracle 118085 1 0 21:33 ? 00:00:00 ora_p007_cdb1
oracle 118087 1 0 21:33 ? 00:00:00 ora_w003_cdb1
oracle 118096 1 0 21:34 ? 00:00:00 ora_w004_cdb1
oracle 118102 1 0 21:34 ? 00:00:00 ora_qm02_cdb1
oracle 118106 1 0 21:34 ? 00:00:01 ora_q002_cdb1
oracle 118108 1 0 21:34 ? 00:00:00 ora_q003_cdb1
oracle 118290 1 0 21:34 ? 00:00:00 ora_m001_cdb1
oracle 118292 1 0 21:34 ? 00:00:01 ora_m002_cdb1
oracle 118294 1 0 21:34 ? 00:00:00 ora_m003_cdb1
oracle 118314 1 0 21:34 ? 00:00:01 ora_cjq0_cdb1
oracle 118516 118370 0 21:40 pts/4 00:00:00 grep --color=auto cdb1
[oracle@oracle-db-19c ~]$ 查看Oracle归档进程
[oracle@oracle-db-19c ~]$ ps -ef | grep arc
oracle 118591 118370 0 21:41 pts/4 00:00:00 grep --color=auto arc
[oracle@oracle-db-19c ~]$ 查看Oracle归档是否开启
SQL>
SQL> show user
USER is "SYS"
SQL>
SQL> archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /u01/app/oracle/product/19.3.0/dbhome_1/dbs/arch
Oldest online log sequence 80
Current log sequence 82
SQL> 将Oracle归档开启的方法
SQL>
SQL> show user
USER is "SYS"
SQL>
SQL> archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /u01/app/oracle/product/19.3.0/dbhome_1/dbs/arch
Oldest online log sequence 80
Current log sequence 82
SQL>
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.
Total System Global Area 629145392 bytes
Fixed Size 9137968 bytes
Variable Size 197132288 bytes
Database Buffers 406847488 bytes
Redo Buffers 16027648 bytes
Database mounted.
SQL> alter database archivelog;
Database altered.
SQL> alter database open;
Database altered.
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u01/app/oracle/product/19.3.0/dbhome_1/dbs/arch
Oldest online log sequence 80
Next log sequence to archive 82
Current log sequence 82
SQL> 查看Oracle归档进程
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ ps -ef | grep arc
oracle 119280 1 0 22:01 ? 00:00:00 ora_arc0_cdb1
oracle 119284 1 0 22:01 ? 00:00:00 ora_arc1_cdb1
oracle 119286 1 0 22:01 ? 00:00:00 ora_arc2_cdb1
oracle 119288 1 0 22:01 ? 00:00:00 ora_arc3_cdb1
[oracle@oracle-db-19c ~]$ 3.启停的体会
参数文件及控制文件和数据库的启动与关闭是息息相关的，数据库的启动可分为三个阶段，分别nomount、mount和open.
在启动的过程中可以直接输入startup启动，也可以startup nomount、startup mount和alter database open三步分别启动。
① startup nomount阶段
Oracle必须读取到数据库的参数文件（pfile或者spfile），如果读不到该参数文件，数据库根本无法nomount成功。如果读到参数文件，将完成一件非常重要的事，就是根据参数文件中的内存分配策略分配相应的内存区域，并启动相应的后台进程。换言之，创建实例instance.
查看Oracle的spfile参数情况
SQL> show user
USER is "SYS"
SQL> show parameter spfile;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
spfile string /u01/app/oracle/product/19.3.0
/dbhome_1/dbs/spfilecdb1.ora
SQL>② startup mount阶段
实例已经创建了，Oracle继续根据参数文件中描述的控制文件的名称及位置，去查找控制文件，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，所以Oracle成功锁定控制文件，就为后续读取操作这些文件打下了基础，锁定控制文件成功就表示数据库mount成功，为实例和数据库之间桥梁的搭建打下了基础。
③ alter database open阶段
“根据控制文件记录的信息，定位到数据库文件、日志文件等，从而正式打通了实例和数据库之间的桥梁。
Oracle启动的三个步骤
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL> startup nomount
ORACLE instance started.
Total System Global Area 629145392 bytes
Fixed Size 9137968 bytes
Variable Size 197132288 bytes
Database Buffers 406847488 bytes
Redo Buffers 16027648 bytes
SQL>
SQL> alter database mount;
Database altered.
SQL>
SQL> alter database open;
Database altered.
SQL> 关闭Oracle
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> 观察Oracle关闭后的共享内存情况
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 8 oracle 600 524288 2 dest
[oracle@oracle-db-19c ~]$ 观察Oracle进程情况
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ ps -ef | grep cdb1
oracle 120526 117684 0 22:25 ? 00:00:00 oraclecdb1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 120545 118370 0 22:27 pts/4 00:00:00 grep --color=auto cdb1
[oracle@oracle-db-19c ~]$ 启动Oracle到nomount状态
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jan 2 22:28:13 2023
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup nomount
ORACLE instance started.
Total System Global Area 629145392 bytes
Fixed Size 9137968 bytes
Variable Size 197132288 bytes
Database Buffers 406847488 bytes
Redo Buffers 16027648 bytes
SQL> 观察Oracle启动后内存分配和进程情况
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 8 oracle 600 524288 2 dest
0x00000000 21 oracle 600 9138176 68
0x00000000 22 oracle 600 603979776 34
0x00000000 23 oracle 600 16027648 34
0x8239f754 24 oracle 600 16384 34
[oracle@oracle-db-19c ~]$ ps -ef | grep cdb1
oracle 120587 1 0 22:28 ? 00:00:00 ora_pmon_cdb1
oracle 120589 1 0 22:28 ? 00:00:00 ora_clmn_cdb1
oracle 120591 1 0 22:28 ? 00:00:00 ora_psp0_cdb1
oracle 120593 1 0 22:28 ? 00:00:00 ora_vktm_cdb1
oracle 120597 1 0 22:28 ? 00:00:00 ora_gen0_cdb1
oracle 120599 1 0 22:28 ? 00:00:00 ora_mman_cdb1
oracle 120603 1 0 22:28 ? 00:00:00 ora_gen1_cdb1
oracle 120606 1 0 22:28 ? 00:00:00 ora_diag_cdb1
oracle 120608 1 0 22:28 ? 00:00:00 ora_ofsd_cdb1
oracle 120611 1 0 22:28 ? 00:00:00 ora_dbrm_cdb1
oracle 120613 1 0 22:28 ? 00:00:00 ora_vkrm_cdb1
oracle 120615 1 0 22:28 ? 00:00:00 ora_svcb_cdb1
oracle 120617 1 0 22:28 ? 00:00:00 ora_pman_cdb1
oracle 120619 1 0 22:28 ? 00:00:00 ora_dia0_cdb1
oracle 120621 1 0 22:28 ? 00:00:00 ora_dbw0_cdb1
oracle 120623 1 0 22:28 ? 00:00:00 ora_lgwr_cdb1
oracle 120625 1 0 22:28 ? 00:00:00 ora_ckpt_cdb1
oracle 120627 1 0 22:28 ? 00:00:00 ora_lg00_cdb1
oracle 120629 1 0 22:28 ? 00:00:00 ora_smon_cdb1
oracle 120631 1 0 22:28 ? 00:00:00 ora_lg01_cdb1
oracle 120633 1 0 22:28 ? 00:00:00 ora_smco_cdb1
oracle 120635 1 0 22:28 ? 00:00:00 ora_reco_cdb1
oracle 120637 1 0 22:28 ? 00:00:00 ora_w000_cdb1
oracle 120639 1 0 22:28 ? 00:00:00 ora_lreg_cdb1
oracle 120641 1 0 22:28 ? 00:00:00 ora_w001_cdb1
oracle 120643 1 0 22:28 ? 00:00:00 ora_pxmn_cdb1
oracle 120647 1 0 22:28 ? 00:00:00 ora_mmon_cdb1
oracle 120649 1 0 22:28 ? 00:00:00 ora_mmnl_cdb1
oracle 120651 1 0 22:28 ? 00:00:00 ora_d000_cdb1
oracle 120653 1 0 22:28 ? 00:00:00 ora_s000_cdb1
oracle 120655 1 0 22:28 ? 00:00:00 ora_tmon_cdb1
oracle 120656 120581 0 22:28 ? 00:00:00 oraclecdb1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 120659 1 0 22:28 ? 00:00:00 ora_m000_cdb1
oracle 120661 1 0 22:28 ? 00:00:00 ora_m001_cdb1
oracle 120726 118370 0 22:29 pts/4 00:00:00 grep --color=auto cdb1
[oracle@oracle-db-19c ~]$ 4.文件的体会
“没有参数文件，无法创建实例，数据库无法 nomount 成功；没有控制文件，数据库无法mount；没有数据文件，数据库无法打开使用（此外没有了数据文件，数据也没地方保存了，数据库也失去意义了）；没有日志和归档文件，数据库就失去了保护伞，变得很不安全。因此所有这些文件都非常重要。
查看参数文件、控制文件、数据文件、日志文件、归档文件和告警文件
参数文件位置：
SQL> show user
USER is "SYS"
SQL>
SQL>
SQL> show parameter spfile;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
spfile string /u01/app/oracle/product/19.3.0
/dbhome_1/dbs/spfilecdb1.ora
SQL> 控制文件位置：
SQL>
SQL> show user
USER is "SYS"
SQL> show parameter control
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
control_file_record_keep_time integer 7
control_files string /u02/oradata/CDB1/control01.ct
l, /u02/oradata/CDB1/control02
.ctl
control_management_pack_access string DIAGNOSTIC+TUNING
SQL> 数据文件位置：
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jan 2 22:38:11 2023
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
SQL> select file_name from dba_data_files;
FILE_NAME
--------------------------------------------------------------------------------
/u02/oradata/CDB1/system01.dbf
/u02/oradata/CDB1/sysaux01.dbf
/u02/oradata/CDB1/undotbs01.dbf
/u02/oradata/CDB1/users01.dbf
SQL> 日志文件位置:
SQL>
SQL> select group#,member from v$logfile;
GROUP#
----------
MEMBER
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
3
/u02/oradata/CDB1/redo03.log
2
/u02/oradata/CDB1/redo02.log
1
/u02/oradata/CDB1/redo01.log
SQL> 归档文件位置：
SQL> show user
USER is "SYS"
SQL>
SQL> show parameter recovery;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
db_recovery_file_dest string
db_recovery_file_dest_size big integer 0
recovery_parallelism integer 0
remote_recovery_file_dest string
SQL> 警告日志文件（位于bdump目录下，以alert大头的文件）
SQL>
SQL> set linesize 1000
SQL> show parameter dump
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
background_core_dump string partial
background_dump_dest string /u01/app/oracle/product/19.3.0
/dbhome_1/rdbms/log
core_dump_dest string /u01/app/oracle/diag/rdbms/cdb
1/cdb1/cdump
max_dump_file_size string unlimited
shadow_core_dump string partial
user_dump_dest string /u01/app/oracle/product/19.3.0
/dbhome_1/rdbms/log
SQL> [oracle@oracle-db-19c ~]$ cd /u01/app/oracle/product/19.3.0//dbhome_1/rdbms/log
[oracle@oracle-db-19c log]$ ls -lart alert*
-rw-r-----. 1 oracle oinstall 138 Nov 30 10:26 alert_cdb1.log
[oracle@oracle-db-19c log]$ 5.监听的体会
lsnrctl status命令是查看监听状态的命令，其中Listener Parameter File和Listener Log File定位了监听文件listener.ora以及对应的日志：
[oracle@oracle-db-19c ~]$ lsnrctl status
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 02-JAN-2023 22:44:06
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle-db-19c)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date 30-NOV-2022 20:33:47
Uptime 33 days 2 hr. 10 min. 19 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/19.3.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/oracle-db-19c/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle-db-19c.centlinux.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Services Summary...
Service "86b637b62fdf7a65e053f706e80a27ca" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cdb1" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cdb1XDB" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cndbapdb" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cndbapdb2" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cndbapdb3" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cndbapdb4_fresh" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "cndbapdb6" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "ec78d5cef183e2dbe0538a08a8c09e00" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "ee89fbf58254959fe0538a08a8c0629a" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "ee926813d203a023e0538a08a8c0e91e" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "ee926813d209a023e0538a08a8c0e91e" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "ee966433cff1b7d7e0538a08a8c04375" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "eea6240cf3422d52e0538a08a8c0c03f" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "eecfd8030e829ae2e0538a08a8c02b62" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "pdb1" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
Service "pdb2" has 1 instance(s).
Instance "cdb1", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@oracle-db-19c ~]$ lsnrctl stop命令是关闭监听的命令：
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ lsnrctl stop
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 02-JAN-2023 22:45:39
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle-db-19c)(PORT=1521)))
The command completed successfully
[oracle@oracle-db-19c ~]$ 查看关闭Oracle监听后的情况
[oracle@oracle-db-19c ~]$ lsnrctl stop
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 02-JAN-2023 22:45:39
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle-db-19c)(PORT=1521)))
The command completed successfully
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ lsnrctl status
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 02-JAN-2023 22:46:05
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle-db-19c)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 2: No such file or directory
[oracle@oracle-db-19c ~]$ 开启ORACLE监听
[oracle@oracle-db-19c ~]$
[oracle@oracle-db-19c ~]$ lsnrctl start
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 02-JAN-2023 22:47:05
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Starting /u01/app/oracle/product/19.3.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 19.0.0.0.0 - Production
System parameter file is /u01/app/oracle/product/19.3.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/oracle-db-19c/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle-db-19c.centlinux.com)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle-db-19c)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date 02-JAN-2023 22:47:06
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/19.3.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/oracle-db-19c/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle-db-19c.centlinux.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
The listener supports no services
The command completed successfully
[oracle@oracle-db-19c ~]$ ![P1827 [USACO3.4] 美国血统 American Heritage](https://img-blog.csdnimg.cn/5a47c30d5c244b23a1906a9544e832e9.png)
