LIST is doing a read-only access. It will update the header with the read accesses when the list either finishes or is terminated. Otherwise, nobody would be able to update the header unless everybody closes the file at some point. You could even write data to the file and it would update as soon as your program finishes. It's only the file header locking that would get in the way but those are so fast that you'll never notice a delay.
Bob Woodward Programmer/Analyst Harbor Wholesale Grocery [EMAIL PROTECTED] > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:owner-u2- > [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] > Sent: Thursday, November 18, 2004 3:41 PM > To: [EMAIL PROTECTED] > Subject: RE: [U2] RE: [UV] Monitoring file changes > > In a message dated 11/18/2004 5:25:03 PM Eastern Standard Time, "Bob > Woodward" <[EMAIL PROTECTED]> writes: > > >If the file has never been closed, just do a quick LIST on the file. If > >FILE.USAGE is on then when you end the list, you'll at LEAST get some > >read hits on it. > > > >Bob Woodward > > If person A has the file open and person B does a list, is the updated > information writen when person B ends her list? Or when person A finally > closes the file? In other words, is the header information viewable, even > though someone somewhere is still holding the file open? > Will > > > >> -----Original Message----- > >> From: [EMAIL PROTECTED] [mailto:owner-u2- > >> [EMAIL PROTECTED] On Behalf Of Glenn Herbert > >> Sent: Thursday, November 18, 2004 2:04 PM > >> To: [EMAIL PROTECTED] > >> Subject: Re: [U2] RE: [UV] Monitoring file changes > >> > >> Yeah. I said that in a previous email. The question was simply is > >there a > >> way to determine if statistics are enabled and, without having to > >delve > >> into the file header, listing out the statistics using FILE.USAGE is > >the > >> only way to tell. Of course, you are > >> correct that IF statistics collection HAS been enabled, yet the file > >has > >> NEVER been closed, thus no header updates have occurred..... > >> > >> Ok. Tried this. Statistics collection can definitely be determined > >using > >> the FILE.USAGE command. If they are enabled, the listing will also > >> include > >> a line such as: > >> > >> Statistics last reset <timestamp> > >> > >> (Statistics last reset Thu Nov 18 17:06:33 2004) > >> > >> IF this line does NOT appear, statistics collection is definitely OFF. > >> > >> > >> > >> At 04:22 PM 11/18/2004, you wrote: > >> >I don't think that's correct. I did some tests on this several years > >ago. > >> >If memory serves, when file usage is ON, counts are held in memory. > >They > >> >don't actually get written to the file header on disk until the file > >is > >> closed. > >> > > >> >Or am I mis-remembering again? > >> > > >> >-- > >> > > >> >Regards, > >> > > >> >Clif > >> > > >> >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> >W. Clifton Oliver, CCP > >> >CLIFTON OLIVER & ASSOCIATES > >> >Tel: +1 619 460 5678 Web: www.oliver.com > >> >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> > > >> > > >> >Glenn Herbert wrote: > >> > > >> >>I believe if you run FILE.USAGE <filename> and all values are zero, > >then > >> >>statistic collection is OFF. You enable it using FILE.USAGE.CLEAR; > >> >>disable it using FILE.USAGE.OFF. > >> >>At 02:54 PM 11/18/2004, you wrote: > >> >> > >> >>>Is there a way to tell if FILE.USAGE has been set to collect > >> information? > >> >>>-Dianne > >> >------- > >> >u2-users mailing list > >> >[EMAIL PROTECTED] > >> >To unsubscribe please visit http://listserver.u2ug.org/ > >> ------- > >> u2-users mailing list > >> [EMAIL PROTECTED] > >> To unsubscribe please visit http://listserver.u2ug.org/ > >------- > >u2-users mailing list > >[EMAIL PROTECTED] > >To unsubscribe please visit http://listserver.u2ug.org/ > ------- > u2-users mailing list > [EMAIL PROTECTED] > To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/
