Unable to change MEMORY_MAX_TARGET (无法修改MEMORY_MAX_TARGET)

alter system set memory_max_target=0 scope=spfile;
shutdown immediate
startup
SQL> show parameter target

memory_max_target big integer 3824M

Logon Storm and Memory shortage issue ORA-07445 dbgtrReserveSpace (记录一次登录风暴致内存不足的问题)

Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x10] [PC:0x938E8C5, dbgtrReserveSpace()+99] [flags: 0x0, count: 1]
Errors in file /oracle/diag/rdbms/ora11g/ora11g/trace/ora11g_ora_13864.trc (incident=60801):
ORA-07445: exception encountered: core dump [dbgtrReserveSpace()+99] [SIGSEGV] [ADDR:0x10] [PC:0x938E8C5] [Address not mapped to object] []
Incident details in: /oracle/diag/rdbms/ora11g/ora11g/incident/incdir_60801/ora11g_ora_13864_i60801.trc
Use ADRCI or Support Workbench to package the incident.

SHELL:Find Memory Usage In Linux (统计每个程序内存使用情况)

shell统计linux系统中每个程序的内存使用情况,因为内存结构非常复杂,不一定100%精确,

scn format (scn格式)

scn(system change number) 结构主要维护 oracle数据库内部的数据一致性,SCN 有两部分组成: Base and wrap,wrap 是16bit的数字,base是32bit的数字,这样其实就可以算scn的有效范围,它的格式(redo dump trace)是wrap.base,当base超过了2的32次方,然后wrap 就会加1,其实用sql 很好验证。

SQL Test Case Builder generate test case automatically(自动生成SQL所需测试数据)

Why SQL Test Case Builder? For most SQL problems, the s […]

ORA-00313,ORA-00312,ORA-27037,ORA-19527 DATAGARD 11G r2

Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
DDE: Problem Key ‘ORA 312’ was flood controlled (0x5) (no incident)
ORA-00312: online log 2 thread 1: ‘/oracle/oradata/icme/redo02.log’
Error 19527 creating/clearing online redo logfile 2