Directpathsync wait event

Directpathsync wait event

Encounter direct path sync wait event

When using hvr to test Big Table synchronization, encounter direct path sync wait event, after querying the official documentation, http://docs.oracle.com/cd/E11882_01/server.112/e40402/waitevents003.htm#REFRN00538
It is described as follows:

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

The above description shows the waiting time for the fsync operation to finish writing.

Here is an additional sentence:
This wait event starts from 10.2.0.5 and is tested as follows:

Microsoft Windows [version 6.1.7600] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C: \ Users \ Administrator> f: F: \> cd oracle \ product \ 10.2.0 \ db_1 \ BINF: \ oracle \ product \ 10.2.0 \ db_1 \ BIN> set oracle_sid = fsF: \ oracle \ product \ 10.2.0 \ db_1 \ BIN> net start oracleservicefsOracleServiceFS service is starting .................. the OracleServiceFS service has been started successfully. F: \ oracle \ product \ 10.2.0 \ db_1 \ BIN> sqlplus/as sysdbaSQL * Plus: Release 10.2.0.4.0-Production on Sat May 30 21:30:02 2015 ------> 10.2.0.4Copyright (c) 1982,200 7, oracle. all Rights Reserved. connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0-64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options21: 30: 58 sys @ FS> col name format a3021: 31: 05 sys @ FS> col wait_class format a3021: 31: 20 sys @ FS> select name, wait_class from v $ event_name where name like '% direct path % '; NAME WAIT_CLASS ------------------------------ ---------------------------- direct path read User I/Odirect path read temp User I/Odirect path write temp User I/OElapsed: 00:00:00. 0021:3:21 sys @ FS>

[Oracle @ lei1 ~] $ Sqlplus/as sysdbaSQL * Plus: Release 10.2.0.5.0-Production on Sun May 31 05:37:11 2015 Copyright (c) 1982,201 0, Oracle. all Rights Reserved. connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.5.0-64bit Production ----------> 10.2.0.5With the Partitioning, OLAP, data Mining and Real Application Testing optionsSQL> set line 200SQL> col name format a30SQL> col wait_class format a30SQL> select name, wait_class from v $ event_name where name like '% direct path % '; NAME WAIT_CLASS begin ------------------------------ direct path sync User I/O -------------------> This waits for the event direct path read User I/Odirect path read temp User I/Odirect path write temp user I/OSQL>