Wait Events : checkpoint busy waits or archiver busy waits

While such wait events occur  in AlertLog file, one must consider to proceed with ARCHIVER TUNING

1. Check the number of Online Redolog Members and size of the online redo logs. 

Excessive size and the number of online redo log groups will give archiver more time to catch up. Hence Adding more online logs does not help a situation where the archiver cannot keep up with LGWR process.

It can help if there are bursts of redo generation since it gives ARCH more time to average its processing rate over time.

2. In such cases you can add multiple archiver (ARCh) processes

Create 'alter system archive log all'. This will spawn archive processes at some fixed interval may be required. These processes once spawned will assist archiver in archiving any un-archived log in that thread of redo. Once it has been completed, the temporary processes will go away.

3. Evaluate checkpoint interval and frequency

There are several possible actions include adding DBWR processes,  increasing db_block_checkpoint_batch, reducing db_block_buffers. Turning on or allowing async IO capabilities definitely helps alleviate most DBWR inefficiencies.

4. Check OS supportability of asynchronous I/Os

Async reads should help tremendously. Async writes may help if OS supports asynchronous I/Os on file systems.

You can check with your vendor if the current version of your operating system supports async IO to file systems (ufs).

5. Check for system or IO contention.

Check CPU waits and usage, disk  level bottlenecks. Also check operating system manuals for the appropriate commands to monitor system performance.

For example, you can use UNIX  commands such as "sar  5 5 5"  “sar –d ”or "iostat" to identify disk bottlenecks.