Database Configuration and I/O Issues(3)

Regulating Checkpoint Queue
调整checkpoint队列


有如下参数
FAST_START_TO_TARGET
LOG_CHECKPOINT_INTERVAL 过时
LOG_CHECKPOINT_TIMEOUT 过时
FAST_START_MTTR_TARGET


实例恢复速度与日常运行效率的权衡。
实际情况是掉电情况比较少，所以多点增量checkpoint比


较好，即平时写比较多的日志，才写磁盘。所以要调整脏


数据队列的长度。
FAST_START_MTTR_TARGET=600，则600秒就大概能实例恢复


。


Redo Groups and Members
同一组中的几个redo log file应该放在不同的磁盘上。
设足够的组以防止归档等待。
v$logfile
v$log
v$log_history


Archiving Performance
1.Allow the LGWR process to write to a disk


different from the one the ARCn process is reading.
2.Share the archiving work during a temporary


increase in workload:
alter system archive log all to



3.Increse the number of archive processes.
4.Change archiving speed:参数
LOG_ARCHIVE_MAX_PROCESSES
LOG_ARCHIVE_DEST_n
动态性能视图以助诊断：
v$archive_dest
v$archived_log
v$archive_processes
LOG_ARCHIVE_DEST_STATE_n