RE: I/O and db_file_multiblock_read_count

From: Kevin Closson <kevinc_at_polyserve.com>
Date: Tue, 12 Dec 2006 10:56:01 -0800
Message-ID: <5D2570CAFC98974F9B6A759D1C74BAD001C33796@ex2.ms.polyserve.com>

ahhh... I haven't touched Sol in 5 years...I guess it shows! Thanks, Matt

---

	From: Matthew Zito [mailto:mzito_at_gridapp.com] 
	Sent: Tuesday, December 12, 2006 9:51 AM
	To: kevinc_at_polyserve.com; oracle-l
	Subject: RE: I/O and db_file_multiblock_read_count
	
	
	Nono, its just that on Linux, let's say, cat S.dbf > /dev/null

is fast, but an strace will show that its actually doing a stream of write()s to the device. On solaris, it does something like (horrible perl-ish pseudocode):          

	if ( dest == /dev/null) {
	    exit 0;
	} else {
	    write(contents, dest);
	}
	 
	 
	Matt




________________________________


		From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin Closson
		Sent: Tuesday, December 12, 2006 12:45 PM
		To: oracle-l
		Subject: RE: I/O and db_file_multiblock_read_count
		
		
		what? can't dump junk in the bit bucket on Sol? I must

not be gettign your point

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			From: Matthew Zito [mailto:mzito_at_gridapp.com] 
			Sent: Tuesday, December 12, 2006 9:40 AM
			To: kevinc_at_polyserve.com; oracle-l
			Subject: RE: I/O and

db_file_multiblock_read_count                                                  

                        /dev/null is hard, as some OS'es, solaris notably, do evil tricks with certain utilities (like cat something to /dev/null - it returns immediately). Not sure about dd

---

                                From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin Closson                                 

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Received on Tue Dec 12 2006 - 12:56:01 CST