该warning是在j001.trc文件里边的
平台信息如下（该信息也是来源于j001.trc文件）
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing optionsWindows NT Version V6.1 CPU : 64 - type 8664, 32 Physical Cores
搜索mos,得到如下文章：
'Warning:Could not Lower the Asynch I/O Limit to 224 for SQL direct I/O. It is set to -1' After Upgrading To 10.2.0.5 (Doc ID 1155445.1)Bug 9772888 - Needless "WARNING:Could not lower the asynch I/O limit to .. for SQL direct I/O It is set to -1" messages (Doc ID 9772888.8)
在上述文章中，该warning被定位为bug：
This seems due to Bug 9772888 - WARNING:COULD NOT LOWER THE ASYNCH I/O LIMIT TO 160 FOR SQL DIRECT I/OSame behavior appears and on the same platform 10.2.0.5
当然，该bug并非针对windows平台：
| Product (Component) | Oracle Server (Rdbms) |
| Range of versions believed to be affected | Versions >= 10.2.0.5 but BELOW 12.1 |
| Versions confirmed as being affected |
|
| Platforms affected | Generic (all / most platforms affected) |
解决该bug的方法：
Solution
To implement a solution for Bug:9772888, please execute any of the below alternative solutions:
- Upgrade to 11.2.0.2 or higher
OR
- Download and apply interim Patch:9772888, if available for your platform and RDBMS release. To check for conflicting patches, please use the MOS Patch Planner Tool. For the Microsoft Windows platform this issue is fixed in patch bundle 1 and higher on top of the 10.2.0.5 release. If no patch is available, file a Service Request through My Oracle Support for your specific Oracle version and platform.
This issue is fixed in
- 12.1.0.1 (Base Release)
- 11.2.0.2 (Server Patch Set)
- 10.2.0.5.2 Database Patch Set Update
- 10.2.0.5 Patch 1 on Windows Platforms
这个案例也说明：打psu（非windows平台）或者bundle patch（windows平台）的重要性！