分类： Oracle
2011-03-13 13:34:17
| Wait Name | Description | Tuning Tips |
|---|---|---|
| log file sequential read | Coordinator (recovery session or MRP process) wait for log file read I/O | Tune log read I/O |
| px deq: par recov reply | Coordinator synchronous wait for slave (wait for checkpoints) | Tune datafile write I/O, increase DBWR processes, increase primary/standby redo log size |
| px deq credit: send blkd | Coordinator streaming wait for slave (wait for apply) | Increase PARALLEL_EXECUTION_MESSAGE_SIZE to 8192 |
| free buffer waits | Foreground waiting available free buffer in the buffer cache | Increase DB_CACHE_SIZE and remove any KEEP or RECYCLE POOL settings |
| recovery read | Wait for data block read | Tune datafile read I/O |
| direct path read | Coordinator wait for file header read at log boundary checkpoint | Tune datafile read I/O |
| direct path write | Coordinator wait for file header write at log boundary checkpoint | Tune datafile write I/O |
| checkpoint completed (serial recovery only) | Wait for checkpoint completed | Tune datafile write I/O
Increase number of DBWR processes |
| db file parallel read (serial recovery only) | Wait for data block read | Tune file read I/O |
