文档解释
ORA-00083: warning: possibly corrupt SGA mapped
Cause: Even though there may be SGA corruptions, the SGA was mapped.
Action: Use the DUMPSGA command to dump the SGA.
官方解释
ORA-00083 warning: possibly corrupt SGA mapped
Cause: The SGA appears to have been mapped at an address that is contained in an already-freed memory range previously used by an Oracle process. This could have resulted from applying ad-hoc patches to the SGA.
Action: Contact Oracle Support Services with this information.
ORA-00083警告：可能存在SGA映射的损坏
原因：SGA看起来已经映射一个已经被Oracle进程释放的内存地址，这可能是由于应用了SGA的临时补丁而造成的。
操作：向Oracle Support Services提供此信息。
常见案例
1. 如果在关闭实例的过程中的startup postpone参数被设置，可能导致ORA-00083警告。
2. 如果执行alter system set sga_target=0命令之前没有释放当前所有的内存，则可能会引发该警告。
正常处理方法及步骤
1. 关闭警告并重新启动实例：
alter system set events ‘00083 trace name context off’ scope=spfile
2. 确认SGA空间是否正确：
procdump
–查看SGA和PGA地址及它们相应的大小
3. 检查是否有补丁被应用到SGA空间：
cat /var/opt/oracle/orapatch_[patch_name]
–查看是否有补丁被应用到SGA
4. 如果有补丁被应用到SGA，需要进行清理：
$ORACLE_HOME/OPatch/opatch rollback -id [patch_name] 或 opatch prereq check — Main -rollback
5. 重新启动实例：
startup
6. 检查警告是否还存在：
show parameter events
–查看ORA-00083警告是否还存在
