在使用hvr测试 大表同步的时候，遇到direct path sync等待事件，经过查询官方文档，http://docs.oracle.com/cd/E11882_01/server.112/e40402/waitevents003.htm#REFRN00538
有说明如下：
direct path sync
During Direct Path write operations the data is asynchronously written to the database files. At some point the session needs to ensure that all outstanding asynchronous I/O have been completed to disk. On Unix the fsync command, which synchronizes data
to disk, is issued to confirm that all the writes have completed and the data is all on disk.
Wait Time: The time taken for the fsync operation to complete, which normally is the time taken to complete the outstanding I/Os.
| Parameters | Description |
|---|---|
| file# | See "file#" |
| flags | Flags used for debugging purposes |
看上面的说明，是在等待“fsync操作写完毕”的等待时间。
额外说一句：
该等待事件是从10.2.0.5开始有的，如下是测试：
Microsoft Windows [版本 6.1.7600] 版权所有 (c) 2009 Microsoft Corporation。保留所有权利。 C:\Users\Administrator>f: F:\>cd oracle\product\10.2.0\db_1\BIN F:\oracle\product\10.2.0\db_1\BIN>set oracle_sid=fs F:\oracle\product\10.2.0\db_1\BIN>net start oracleservicefs OracleServiceFS 服务正在启动 .................. OracleServiceFS 服务已经启动成功。 F:\oracle\product\10.2.0\db_1\BIN>sqlplus / as sysdba SQL*Plus: Release 10.2.0.4.0 - Production on Sat May 30 21:30:02 2015 ------>10.2.0.4 Copyright (c) 1982, 2007, Oracle. All Rights Reserved. Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options 21:30:58 [email protected]> col name format a30 21:31:05 [email protected]> col wait_class format a30 21:31:20 [email protected]> select name,wait_class from v$event_name where name like '%direct path%'; NAME WAIT_CLASS ------------------------------ ------------------------------ direct path read User I/O direct path read temp User I/O direct path write User I/O direct path write temp User I/O Elapsed: 00:00:00.00 21:31:21 [email protected]>
[[email protected] ~]$ sqlplus / as sysdba SQL*Plus: Release 10.2.0.5.0 - Production on Sun May 31 05:37:11 2015 Copyright (c) 1982, 2010, Oracle. All Rights Reserved. Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production ---------->10.2.0.5 With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> set line 200 SQL> col name format a30 SQL> col wait_class format a30 SQL> select name,wait_class from v$event_name where name like '%direct path%'; NAME WAIT_CLASS ------------------------------ ------------------------------ direct path sync User I/O ------------------->有此等待事件 direct path read User I/O direct path read temp User I/O direct path write User I/O direct path write temp User I/O SQL>
时间： 2025-01-14 15:25:00