怎么注册一个自己的网站,开发公司已经卖出生地,微网站什么意思,动漫制作专业使用的电脑很多时候#xff0c;数据库有故障打不开#xff0c;需要用到推进scn的技术#xff0c;这里介绍下12c及以上版本的oracle怎么推进数据库的scn。 经测试发现#xff0c;数据库mount和open状态下都可以通过此方法推进SCN。 Session1#xff1a; 查询当前SCN SQL select c… 很多时候数据库有故障打不开需要用到推进scn的技术这里介绍下12c及以上版本的oracle怎么推进数据库的scn。 经测试发现数据库mount和open状态下都可以通过此方法推进SCN。 Session1 查询当前SCN SQL select current_scn from v$database; CURRENT_SCN ----------- 2910718245 查询当前SCN转成16进制后的值 SQL select to_char(2910718245,xxxxxxxxxxxx) from dual; TO_CHAR(29107 ------------- ad7e0925 查询预修改的SCN转换成16进制后的值 SQL select to_char(3910718245,xxxxxxxxxxxx) from dual; TO_CHAR(39107 ------------- e918d325 SQL SQL oradebug setmypid Statement processed. SQL oradebug dumpvar sga kcsgscn_ kscn8 kcsgscn_ [060017E98, 060017EA0) AD7E093B 00000000 060017E98是SCN BASE值我们待会修改的就是他修改成多少数据库SCN就是多少 AD7E093B是当前的SCN值可以理解为060017E98是一个代号x当前的x等于AD7E093B Session2: [oracleredhat19c11 ~]$ ps -ef|grep LOCALYES oracle 9824 9730 0 Feb22 ? 00:00:01 oracleorcl (DESCRIPTION(LOCALYES)(ADDRESS(PROTOCOLbeq))) oracle 18621 8636 0 01:18 pts/1 00:00:00 grep --colorauto LOCALYES oracle 20109 20105 0 Feb15 ? 00:00:13 oracletestdb19c (DESCRIPTION(LOCALYES)(ADDRESS(PROTOCOLbeq))) 本次测试库是orcl因此选9824 [oracleredhat19c11 ~]$ gdb $ORACLE_HOME/bin/oracle 9824 GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-114.el7 Copyright (C) 2013 Free Software Foundation, Inc. License GPLv3: GNU GPL version 3 or later The GNU General Public License v3.0- GNU Project - Free Software Foundation This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type show copying and show warranty for details. This GDB was configured as x86_64-redhat-linux-gnu. For bug reporting instructions, please see: 。。。。。。(中间省略) (gdb) set *((int *) 0x060017E98) 0xe918d325 ---将SCN BASE修改为刚才查出来的值 (gdb) quit A debugging session is active. Inferior 1 [process 9824] will be detached. Quit anyway? (y or n) y Detaching from program: /oracle/app/product/19.3.0/db_1/bin/oracle, process 9824 返回session1查询修改成功 SQL select current_scn from v$database; CURRENT_SCN ----------- 3910718287 重启数据库也正常 SQL shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down. SQL startup; ORACLE instance started. Total System Global Area 2466250400 bytes Fixed Size 9137824 bytes Variable Size 603979776 bytes Database Buffers 1845493760 bytes Redo Buffers 7639040 bytes Database mounted. Database opened. SQL select current_scn from v$database; CURRENT_SCN ----------- 3910719415
