Oracle-L: RE: "direct path write" waits, please help

From: DENNIS WILLIAMS <DWILLIAMS_at_LIFETOUCH.COM>
Date: Tue, 29 Jul 2003 08:49:24 -0800
Message-ID: <F001.005C7AAA.20030729084924@fatcity.com>

Hans

I did a search on Google, and found this article: http://www.faqchest.com/prgm/oracle-l/ora-02/ora-0206/ora-020638/ora02062414 _22868.html
(you'll probably have to patch the link together) According to this article, your biggest and second biggest wait may be connected.

Dennis Williams
DBA, 80%OCP, 100% DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com

-----Original Message-----
Sent: Tuesday, July 29, 2003 10:54 AM
To: Multiple recipients of list ORACLE-L

Hi All,

Please help me tune this i/o related wait event. This is my 8.1.6 statspack top-5 wait list:
Top 5 Wait Events

~~~~~~~~~~~~~~~~~                                             Wait     % 
Total
Event                                               Waits  Time (cs)   Wt

Time

-------------------------------------------- ------------ ------------ 
-------
direct path write                                 304,867       35,925   
49.83
log file sync                                     145,015       23,441   
32.52
db file sequential read                            11,370        3,684    
5.11
file open                                             981        3,326    
4.61
db file parallel write                              1,893        3,115

4.32

You'll notice that 'direct path write' is the most expensive one in the list. I cannot find enough info on the net about this wait event, therefore I'm asking the real experts.

What events in Oracle trigger this wait event? In what way is this event different from "db file parallel write"? I mostly read comments that suggest lots of sorting and parallallel queries.

However, most sorts are done in memory and degree = 0 for all tables.

Any suggestions are very welcome.

Thanks,
Hans de Git

MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl

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Author: Hans de Git
INET: hansdegit_at_hotmail.com

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Author: DENNIS WILLIAMS
INET: DWILLIAMS_at_LIFETOUCH.COM

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