Re: Anyone using "use_readv" ?

From: Connor McDonald <mcdonald.connor.cs_at_bhp.com.au> >> Anyone got any stories to tell, good or bad, about the use_readv parameter. <<

You might have explained that use_readv causes Unix to read ahead on file access so that the next block in the Unix buffer before Oracle requests it. This parameter applies to an installation that uses regular Unix files and is not using the more efficient I/O and perfered methods of list I/O, direct I/O, or async I/O.

In simple terms: list I/O passes multiple I/O request to the OS at a time; direct I/O bypasses the Unix buffer pool; and async I/O is non-blocking I/O where the issueing program does other work while the I/O is handled by the OS. The program is responsible for checking to see when the I/O completes.

The only source I know for information on these (other than a good Unix administrator and the system manuals) is the book: Oracle and Unix Performance Tuning by Ahmed Alomari.

I hope this is helpful.

Mark Powell -- Oracle 7 Certified DBA
- The only advice that counts is the advice that you follow so follow your own advice - Received on Wed Mar 25 1998 - 00:00:00 CST