ORA-00445错误一则
数据库在运行中突然出现如下错误，导致服务不可用。
ORA-00445: background process “m000” did not start after 120 seconds
ORA-32701: Possible hangs up to hang ID=0 detected
DIA0 terminating blocker (ospid: 14288486 sid: 4370 ser#: 7549) of hang with ID = 129
requested by master DIA0 process on instance 1
Hang Resolution Reason: Automatic hang resolution was performed to free a
critical database process.
by terminating session sid: 4370 ospid: 14288486
DIA0 successfully terminated session sid:4370 ospid:14288486 with status 31.
ORA-00445: background process “J000” did not start after 120 seconds
ORA-00445: background process “W005” did not start after 120 seconds
ORA-00445: background process “J000” did not start after 120 seconds
ERROR: Unable to normalize symbol name for the following short stack (at offset 311):
初步判断由于相应资源分配不足，导致进程无法启动，进一步分析日志，share_pool内存资源不足造成。
当前数据库为Oracle 11gR2版本，业务为OLAP系统，数据量以TB计算，表即使分区后仍然很大，最终导致问题的是这条SQL语句：
ALTER TABLE ZBA_WWW.WWW_D_PRD_AL_USER_LIST_010 MODIFY DEFAULT ATTRIBUTES FOR
PARTITION PART201304_089 TABLESPACE TBS_ZB_WWW_03 COMPRESS ;
此语句在在线状况下压缩一张分区表,占用大量内存，使得share_pool没有足够的内存给予请求，促使数据库hang起。
通过调整sga大小可初步解决问题。不过问题的原因还是由于对本月正在使用的分区表进行压缩，从而导致了这个分区和用户争抢内存使用造成，这个就不应该了。
