RE: # of datafiles per tablespace

Hi Kim,

Ahamed Alomari (Oracle8i and Unix Performance Tuning p142-143)discusses this in more detail. However I don't think this is more relevant with the Async IO and multiple DB Writers.

But this is a serious issue in older versions (oracle 7 and below) because the number of Asnyc IO thread requests were limited by a kernel constant
(forgot the name btw) and exceeding this fills the alert logs with "Out of
Async IO requests".
This restriction was lifted in Oracle 8.0.3 and I think this is no more a problem.

IIRC the number was 200 (200 requests per process)

Best Regards,
K Gopalakrishnan
Bangalore, INDIA

-----Original Message-----
Smith
Sent: Tuesday, March 05, 2002 5:48 AM
To: Multiple recipients of list ORACLE-L

Do you know of a web site where I could research particular thought on? I have not seen anything like that in my research. Thanks.

-----Original Message-----
rabbit_at_emirates.net.ae
Sent: Monday, March 04, 2002 8:53 PM
To: Multiple recipients of list ORACLE-L

In a UNIX system it is better to have more small size datafiles than a few or one large datafile: The reason is that UNIX aquires an exclusive file write lock and therefore if you use multiple files you will avoid a situation where multiple simultaneous writes to data files become serialized and consequently reduce I/O performance: For example instead of one 2GB Data file , split it into 8 250mb: By the way I am addressing OLTP type systems with this e-mail

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Author: K Gopalakrishnan
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