INFO-VAX Thu, 18 Oct 2007 Volume 2007 : Issue 570 Contents: Re: CHECKSUM oddity? DEFRAG Re: DEFRAG More scaremongering bollocks Re: Rare job posting Re: Rare job posting Re: still not convinced global warming a hoax? Re: still not convinced global warming a hoax? Re: still not convinced global warming a hoax? Re: TCPIP SMTP receiver issues (SYSTEM-F-NOLINKS) Re: TCPIP SMTP receiver issues (SYSTEM-F-NOLINKS) Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: Which delete statement is faster? Re: WOT: (wildly off-topic) Re: Norway - Europe now calls for kindergarden ---------------------------------------------------------------------- Date: Thu, 18 Oct 2007 06:45:51 -0500 From: Jur van der Burg <"vdburg at hotmail dot com"> Subject: Re: CHECKSUM oddity? Message-ID: <4717476e$0$243$e4fe514c@news.xs4all.nl> Read reverse support is done in MKdriver by skipping backwards, reading forwards and skipping backwards again. Very slow and inefficient but it works. Jur. George Cornelius wrote: > In article , koehler@eisner.nospam.encompasserve.org (Bob Koehler) writes: >> In article , cornelius@encompasserve.org (George Cornelius) writes: >>> In article , glen herrmannsfeldt writes: >>>> Another interesting case is the ability to read tapes backwards. >>>> While many newer drives can't do that, most of the older ones did. >>> IBM certainly did it. I used the 2400 series drives, which had that >>> capability, at least on mainframe channels. >>> >> As of the December 2000 doc CD, only TK50 was a supported tape that >> didn't support reading in reverse. I suspect that's changed, but when >> I tried to bring up the latest I/O User's Guide the I didn't wait >> to see how long the doc site would take to respond to the PDF file >> request. > > Actually, I was thinking pre-history - about 10 years before VMS. > > And, yes, the VMS I/O User's Guide seems to list only TK50's, of the various > obsolete drives it claims are supported, as being unable to read backwards. I > just spit an IO$_READPBLK!IO$M_REVERSE at a STK 9840 that had advanced one record > from load point and it happily fetched the VOL1 label into my input buffer, so > VMS read reverse support is alive and well. > > -- > George Cornelius cornelius(at)eisner.decus.org > cornelius(at)mayo.edu > > >> I wouldn't expect 8mm to read in reverse, either, but those never made >> it to full support. >> ------------------------------ Date: Thu, 18 Oct 2007 10:50:27 -0500 From: Ron Johnson Subject: DEFRAG Message-ID: <9hLRi.19192$UN.17317@newsfe24.lga> Hi, Is DFO really separately-purchased kit? -- Ron Johnson, Jr. Jefferson LA USA Give a man a fish, and he eats for a day. Hit him with a fish, and he goes away for good! ------------------------------ Date: Thu, 18 Oct 2007 13:22:20 -0400 From: Robert Deininger Subject: Re: DEFRAG Message-ID: In article <9hLRi.19192$UN.17317@newsfe24.lga>, Ron Johnson wrote: > Hi, > > Is DFO really separately-purchased kit? I believe it is. It doesn't seem to be included in any of the Integrity operating environment license bundles. I don't know if it's part of any of the Alpha bundles. http://h71000.www7.hp.com/openvms/storage/dfopage.html ------------------------------ Date: Thu, 18 Oct 2007 21:18:16 +0800 From: "Richard Maher" Subject: More scaremongering bollocks Message-ID: Hi Tom, My guess is that it's a great opportunity for an IMM team-building exercise where they get to build Big-Ben out of Lego. (Given the talent involved there's bound to be a few pieces left over, and as soon as it looks like a deliverable is on the horizon the venue will probably switched to Pirates of the Caribbean and a big "Yo Ho, Yo Ho, and IMM life for me!") Cheers Richard Maher PS. Don't let Arne (whose knowledge of many things including all OO development and Java in particular I respect immensely) fool ya, they were looking for whole teams of those skills in London this summer (and at TOP DOLLAR) How's JavaFX going? (Says he who's smugly worked out where the GUI future lies :-) "Tom Linden" wrote in message news:op.t0d83bedhv4qyg@murphus.linden... > On Wed, 17 Oct 2007 20:03:03 -0700, Arne Vajhøj wrote: > > > I just saw a job posting in Denmark. > > > > Required skills: VMS, Cobol, ACMS, DECForms, VAX and Alpha. > > > > Long time since I last saw one of those. > > > > Arne > > What was the name of the company? > > -- > PL/I for OpenVMS > www.kednos.com ------------------------------ Date: Thu, 18 Oct 2007 06:06:07 GMT From: =?ISO-8859-1?Q?Jan-Erik_S=F6derholm?= Subject: Re: Rare job posting Message-ID: Arne Vajhøj wrote: > I just saw a job posting in Denmark. > > Required skills: VMS, Cobol, ACMS, DECForms, VAX and Alpha. > > Long time since I last saw one of those. > > Arne In sweden I've seen 1 or 2 jobs postings (culsulting) each months since this summer. Not in the public job postings but on "consulting brookers" web sites. Mainly full time, 6-12 months jobs. Jan-Erik. ------------------------------ Date: Thu, 18 Oct 2007 06:00:37 -0700 From: "Tom Linden" Subject: Re: Rare job posting Message-ID: On Wed, 17 Oct 2007 20:03:03 -0700, Arne Vajhøj wrote: > I just saw a job posting in Denmark. > > Required skills: VMS, Cobol, ACMS, DECForms, VAX and Alpha. > > Long time since I last saw one of those. > > Arne What was the name of the company? -- PL/I for OpenVMS www.kednos.com ------------------------------ Date: Thu, 18 Oct 2007 13:18:49 +0000 (UTC) From: david20@alpha2.mdx.ac.uk Subject: Re: still not convinced global warming a hoax? Message-ID: In article <1192626288.976787.16790@t8g2000prg.googlegroups.com>, AEF writes: >On Oct 17, 7:32 am, b...@cs.uofs.edu (Bill Gunshannon) wrote: >> In article <1192578944.310398.75...@v29g2000prd.googlegroups.com>, >> AEF writes: >> >> > On Oct 16, 8:40 am, b...@cs.uofs.edu (Bill Gunshannon) wrote: >> >> In article <47141695.7CEF3...@spam.comcast.net>, >> >> David J Dachtera writes: >> >> >> > Neil Rieck wrote: >> >> >> >> On Oct 12, 9:00 am, koeh...@eisner.nospam.encompasserve.org (Bob >> >> >> Koehler) wrote: >> >> >> > Congrats to Al Gore and the UN panel on the environment on the >> >> >> > Nobel Peace Prize. >> >> >> >> Some scientists predicted that the long sought after "North West >> >> >> Passage" would be permanently open sometime before 2015. Guess what? >> >> >> It opened last month. >> >> >> >>http://news.bbc.co.uk/1/hi/world/americas/6995999.stm >> >> >> > Folks here probably know how Greenland got its name. >> >> >> Greenland, hell.... Hasn't anyone here ever read aboiut what they find >> >> in core samples taken through the ice in Antarctica? >> >> >> > Suffice it to say - circles are never-ending, and this is the next time around >> >> > this circle, one of many that comprise the cycles of this planet. >> >> >> But espousing that won't get you grant money to study Global Warming. >> >> > Bill, >> >> > Quick question: Suppose global warming really is what the scientists >> > say it is. What would be different that you or I would be able to read >> > of see compared to if it weren't? If you can't come up with some >> > significant difference, you can't rule out GW. >> >> But, based on existing data, I can rule out the supposed >> contribution of man. Major volcanic eruptions like Mt. >> Pinataubo and Mount St. Helens generate more greenhouse >> gases in a short period of time than man has since the >> start of the industrial age (this was measured, I think for >> the first time, when Mt. Pinataubo erupted. The information > Mt Pinataubo resulted in global surface cooling due to the adding of significant quantities of sulphur dioxide into the atmosphere see http://www.cmar.csiro.au/e-print/open/greenhouse_2000e.htm where it also says " Volcanoes are also sources of water vapour and carbon dioxide, but their contribution to the global budgets of greenhouse gases is very small. On the time-scale of decades to centuries, greenhouse gas emissions from volcanic sources cause negligable climate change. However, volcanic emissions of gases such as sulfur dioxide, hydrogen sulfide and hydrogen fluoride are important compared to human-induced sources. These gases have effects on climate (cooling), on stratospheric ozone and possibly on global cloudiness. " The article does say " The climatic impact of the Pinatubo aerosol was stronger than the warming effects of either El Nino or human-induced greenhouse gas changes during 1991-93 " But this is just saying the cooling effect outwayed El Nino and human induced warming. You would probably require an eruption of the yellowstone super volcano to get any significant amount of greenhouse gas emissions and that would be more than offset by the effects of the other gases released. >Can you supply a reference? Where did you learn this from? "More >greenhouse gases" is a bit vague. Can you be more specific? Which >greenhouse gases and how much? > >And if this is true, why doesn't anyone bring this up? Surely the Wall >St. Journal would have a few full-page articles about it! And FOX News >would trumpet it. Etc. All I hear is things like the Weather Service >placing thermometers next to chimneys and down volcanoes and other >nonsense like that. > >> was published widely at the time, but is now buried away as >> it fails to support current trends.) I don't doubt that >> Global Warming exists. I just don't believe the crap put >> out by people like Al Gore who's purpose is anything but >> saving the world. >> >> Go back to my line above: "espousing that won't get you grant money >> to study Global Warming." I read articles everyday about "scientific" >> studies using faked data in order to prolong the flow of grant money. >> I have no reason to believe and lots of evidence to disbelieve that >> this is anything different. The scientific method is dead, long live >> the dollar. > >The dollar didn't work for cold fusion, n-rays, and the fifth force. >These were bogus and were easily shown to be. So science lives. And >most of our whiz-bang technology works based on scientific results. >For example, see recent articles about this year's Nobel prize in >physics, rewarding two scientists who discovered an important >previously unknown property of thin layers of atoms that makes iPods >and the like possible. I don't think iPods would work if this science >were faked. So science is not dead. > >OTOH, there is string theory! But the genius of that is that it is not >testable! Because of the small size postulated for strings it is extremely unlikely to be directly testable in the near future but that doesn't mean that some of it's predictions couldn't be tested see http://newscientist.com/channel/fundamentals/mg19526121.200-string-theory-the-fight-back.html ( This is just the preview and you need to subscribe to see the full article. Unfortunately I wasn't able to find the full article elsewhere. ) David Webb Security team leader CCSS Middlesex University >It is controversial if it is promising and worth further >funding, but if it starts making verifiable predictions, we can test >it and act according to the results. But you still can't rule it out >until you can test it. > >AEF > >> >> bill >> >> -- >> Bill Gunshannon | de-moc-ra-cy (di mok' ra see) n. Three wolves >> b...@cs.scranton.edu | and a sheep voting on what's for dinner. >> University of Scranton | >> Scranton, Pennsylvania | #include > > ------------------------------ Date: Thu, 18 Oct 2007 15:22:40 +0000 (UTC) From: david20@alpha2.mdx.ac.uk Subject: Re: still not convinced global warming a hoax? Message-ID: In article <4716B5C8.F86BB1E2@spam.comcast.net>, David J Dachtera writes: >Bob Koehler wrote: >> >> In article <4715567C.58E31DA4@spam.comcast.net>, David J Dachtera writes: >> >> Repeat after me: >> >> Global warming is both natural and man-made, there is overwhelming evidence. >> [snip] > >Overwhelming, eh... If there were, would we be having this debate? > >Is there proof-positive one way or the other whether warming increases so-called >"green-house" gases or increases in so-called "green-house" gases give rise to >warming? If there is, no one's talking about it. > >Science THINKS gases increase warming, but there's no incontrovertible proof one >way or the other. > John Tyndall conducted experiments in 1859 to discover whether any gases could trap heat rays. He discovered a number that did in particular water vapour and C02. Calculations had already shown that a bare rock at the Earth's distance from the Sun should be far colder than the Earth actually is. See http://www.aip.org/history/climate/co2.htm and http://www.tyndall.ac.uk/general/history/JTyndall_biog_doc.pdf For another data point consider Venus which has an extremely thick atmosphere which consists of mainly carbon dioxide and a small amount of nitrogen. Venus has a surface temperature of 460 degrees celsius which makes it's surface hotter than that of Mercury despite being nearly twice as far from the Sun and receiving only 25% of Mercury's solar irradiance. see http://en.wikipedia.org/wiki/Venus#Atmosphere "no one's talking about it." because there is no debate. The trapping of heat by greenhouse gases was proved by experiment almost 150 years ago. The only debate is how much effect additional human produced Greenhouse gases will have given the complexity of the Earth's climate system. David Webb Security team leader CCSS Middlesex University >-- >David J Dachtera >dba DJE Systems >http://www.djesys.com/ > >Unofficial OpenVMS Marketing Home Page >http://www.djesys.com/vms/market/ > >Unofficial Affordable OpenVMS Home Page: >http://www.djesys.com/vms/soho/ > >Unofficial OpenVMS-IA32 Home Page: >http://www.djesys.com/vms/ia32/ > >Unofficial OpenVMS Hobbyist Support Page: >http://www.djesys.com/vms/support/ ------------------------------ Date: Thu, 18 Oct 2007 15:38:39 +0000 (UTC) From: david20@alpha2.mdx.ac.uk Subject: Re: still not convinced global warming a hoax? Message-ID: In article , david20@alpha2.mdx.ac.uk writes: >In article <4716B5C8.F86BB1E2@spam.comcast.net>, David J Dachtera writes: >>Bob Koehler wrote: >>> >>> In article <4715567C.58E31DA4@spam.comcast.net>, David J Dachtera writes: >>> >>> Repeat after me: >>> >>> Global warming is both natural and man-made, there is overwhelming evidence. >>> [snip] >> >>Overwhelming, eh... If there were, would we be having this debate? >> >>Is there proof-positive one way or the other whether warming increases so-called >>"green-house" gases or increases in so-called "green-house" gases give rise to >>warming? If there is, no one's talking about it. >> >>Science THINKS gases increase warming, but there's no incontrovertible proof one >>way or the other. >> >John Tyndall conducted experiments in 1859 to discover whether any gases >could trap heat rays. He discovered a number that did in particular water >vapour and C02. >Calculations had already shown that a bare rock at the Earth's distance from >the Sun should be far colder than the Earth actually is. > >See > >http://www.aip.org/history/climate/co2.htm > >and > >http://www.tyndall.ac.uk/general/history/JTyndall_biog_doc.pdf > > >For another data point consider Venus which has an extremely thick atmosphere >which consists of mainly carbon dioxide and a small amount of nitrogen. >Venus has a surface temperature of 460 degrees celsius which makes it's >surface hotter than that of Mercury despite being nearly twice as far from >the Sun and receiving only 25% of Mercury's solar irradiance. > >see > >http://en.wikipedia.org/wiki/Venus#Atmosphere > > > >"no one's talking about it." because there is no debate. The trapping of heat >by greenhouse gases was proved by experiment almost 150 years ago. > >The only debate is how much effect additional human produced Greenhouse >gases will have given the complexity of the Earth's climate system. > Just to add one other point. The two propositions you put in place ie warming increases so-called green-house" gases or increases in so-called "green-house" gases give rise to warming? aren't actually in opposition. Greenhouse gases trap heat but a warming of the atmosphere will lead to increased emissions of greenhouse gases from various repositories eg Methane from bogs as the permafrost melts. Rather than being in opposition the two effects re-inforce each other. David Webb Security team leader CCSS Middlesex University ------------------------------ Date: Thu, 18 Oct 2007 10:58:22 +0000 (UTC) From: david20@alpha2.mdx.ac.uk Subject: Re: TCPIP SMTP receiver issues (SYSTEM-F-NOLINKS) Message-ID: In article , JF Mezei writes: >david20@alpha2.mdx.ac.uk wrote: >> But that is the problem with your whole comparison of DECNET versus TCPIP. >> DECNET and TCPIP are communication protocols. NCP or NCL which control how >> DECNET objects are setup and who can set them up are not part of the >> communication protocol they are implementation specific management >> structures. > > >The big difference is that with DECNET, credentials of the calling party >are transmitted to the called party. And the VMS system can then verify >this before even handing the call to the application behind it. A >server process can define its object to accept connections from anyone >and everyone, but you still get credentials of the calling party as part >of the call setup. > You mean the username of the calling party. This is provided during the call-setup because DECNET makes use of proxies. In TCPIP communication proxies are used by the rlogin, rshell etc and they also pass across the username of the calling party. ( And before we get into the side issue of rhost files in user's directories note that this again is an implementation issue DEC TCPIP services centrally manages communication proxies. ) >With TCPIP, all you get is the IP and a port number of the calling party. > See above. For TCP connections all you can reasonably* trust is the IP number and port since you have established two way communication back to that IP number and port. (* I'm ignoring blind spoofing and connection hijacking possibilities). For UDP connections even this level of trust isn't available. I can't imagine that DECNET is any better than TCP in this regard. All you can reasonably trust is the address of the machine with which you have established two-way communication. >It can be argued that the credentials can be faked, especially if the >calling party doesn't run VMS and uses some hacked DECNET stack. > >There can be *some* security in TCPIP. For instance, the OSU web server >has a management utility that uses a predermined port to make the >outgoing call FROM. So the web server process then ensures that a >management request comes from a port defined in the configuration. If >that config specifies a port that is less than 1024, then the person >using the management client must have privileges to enable the >management client to use a known port number for its outgoing port. (for >instance, client connects from port 930 on his node to port 80 on the >web server's node). > I believe the default is port 931. It also defaults to the management host being the localhost. > > > >> It would be entirely possible to implement a version of those DECNET management >> structures which would allow unprivileged users to setup DECNET objects > >But it would not be possible on VMS itself. If by the above you mean implementing a version of the DECNET management structures which would allow unprivileged users to setup DECNET objects then of course it could be done on VMS. Just write a program , make it available (w:re) and then install it with privileges. If you altered file permissions and installed a few programs with privileges you could probably get NCL or NCP usable by unprivileged users (not that i'd recommend it because those programs are much too powerful and complicated for end-user use. A specially written program which restricted the user as to what DECNET objects they could create and manipulate would be much better/safer ie Only allowing them to manipulate DECNET objects and at the very least not allowing them to alter any of the standard DECNET objects setup by the system manager ). David Webb Security team leader CCSS Middlesex University ------------------------------ Date: Thu, 18 Oct 2007 12:42:02 +0000 (UTC) From: david20@alpha2.mdx.ac.uk Subject: Re: TCPIP SMTP receiver issues (SYSTEM-F-NOLINKS) Message-ID: In article , koehler@eisner.nospam.encompasserve.org (Bob Koehler) writes: >In article , david20@alpha2.mdx.ac.uk writes: >> >> But that is the problem with your whole comparison of DECNET versus TCPIP. >> DECNET and TCPIP are communication protocols. NCP or NCL which control how >> DECNET objects are setup and who can set them up are not part of the >> communication protocol they are implementation specific management >> structures. >> It would be entirely possible to implement a version of those DECNET management >> structures which would allow unprivileged users to setup DECNET objects > > You don't get it, do you? TCP/IP connections only require a host and > port, then it's up to the application to decide if it cares about > security. The system admin usually can't change that, unless he can > add something like what Linux provides. > Oh I get it and I agree that centralised control is better - which is why I talked about firewalls providing that control. But it seems you still don't get it. It is what is running listening on the port which decides whether it requires a username and password. Hence FTP (anonymous FTP is a bit of a cheat since it requires a username and password but doesn't use them for traditional authentication), TELNET, SSH etc require the caller to provide login information SMTP generally doesn't (though can be required to do so if the SMTP server is setup to require it). Similarly on VMS with Decnet the program can require the username and password to be supplied or as with MAIL can not require it. DECNET in the call-setup passes the caller username but then so do those TCPIP services which use proxies. The distinction between who can and cannot setup the access which those programs require is NOT a PROTOCOL ISSUE it is a management structure issue and is implementation specific. ( As to TCPIP passing the calling host - or more specifically calling IP address - and calling port number. Those are the only things which can be reasonably authenticated - via the three-way handshake employed with TCP. Over and above that you have to move into the areas of shared-secrets or public/private keys to provide mutual authentication. DECNET doesn't even provide any encryption options let alone these types of facilities. ) David Webb Security team leader CCSS Middlesex University > The DECnet protocol for establishing communications includes a > username and password. Only the system admin can tell the system > to accept blanks. The unprivileged programmer can't change that. > Only a privileged username can set up DECnet management structures > such that unprivileged users could add DECnet objects. Being > thoroughly familiar with those structures and thier APIs, I feel > its a programming challenge to create that problem. > ------------------------------ Date: Thu, 18 Oct 2007 08:00:41 +0200 From: "Rudolf Wingert" Subject: Re: Which delete statement is faster? Message-ID: <004401c8114c$37104920$994614ac@domina.fom> Hello, I think, that the fastest delete is the following: BACKUP/DELETE A*.*;* NL:T/SAVE/NOCRC/GROUP=0 AFAIK this will do all what you want in the right way (reverse order of delete). Best regards Rudolf Wingert ------------------------------ Date: Thu, 18 Oct 2007 03:24:15 -0400 From: JF Mezei Subject: Re: Which delete statement is faster? Message-ID: <4f818$47170a22$cef8887a$14816@TEKSAVVY.COM> Rudolf Wingert wrote: > BACKUP/DELETE A*.*;* NL:T/SAVE/NOCRC/GROUP=0 > AFAIK this will do all what you want in the right way (reverse order of > delete). Out of curiosity, how does Backup achieve this reverse delete ? Does it build an in-memory list of files processed and once the backup has been done (and optional verification pass), it parses that in-mmory list backwards to delete the files ? ------------------------------ Date: Thu, 18 Oct 2007 02:47:18 -0500 From: Ron Johnson Subject: Re: Which delete statement is faster? Message-ID: On 10/18/07 01:00, Rudolf Wingert wrote: > Hello, > I think, that the fastest delete is the following: > BACKUP/DELETE A*.*;* NL:T/SAVE/NOCRC/GROUP=0 > AFAIK this will do all what you want in the right way (reverse order of > delete). But it wastes so much CPU & IO reading thru all the files. $ PIPE DIRE/COL=1/NOHEAD/NOTRAIL DISK$FOO:[BAR]*.* | - SORT/KEY=(POS:1,SIZE:,DESC) SYS$PIPE FOO_BAR.TXT Then DCL to delete them: $ SET NOVER $ ON ERROR THEN $GOTO ERR_RTN $ OPEN/READ IFILE FOO_BAR.TXT $LTOP: $ READ/END=LEND IFILE IREC $ DEL/LOG 'IREC' $ GOTO LTOP $LEND: $ERR_RTN: $ CLOSE IFILE $ EXIT -- Ron Johnson, Jr. Jefferson LA USA Give a man a fish, and he eats for a day. Hit him with a fish, and he goes away for good! ------------------------------ Date: Thu, 18 Oct 2007 11:55:14 -0000 From: Hein RMS van den Heuvel Subject: Re: Which delete statement is faster? Message-ID: <1192708514.301840.225710@t8g2000prg.googlegroups.com> On Oct 18, 3:47 am, Ron Johnson wrote: > On 10/18/07 01:00, Rudolf Wingert wrote: > > > Hello, > > I think, that the fastest delete is the following: > > BACKUP/DELETE A*.*;* NL:T/SAVE/NOCRC/GROUP=0 > > AFAIK this will do all what you want in the right way (reverse order of > > delete). > > But it wastes so much CPU & IO reading thru all the files. > > $ PIPE DIRE/COL=1/NOHEAD/NOTRAIL DISK$FOO:[BAR]*.* | - > SORT/KEY=(POS:1,SIZE:,DESC) SYS$PIPE FOO_BAR.TXT > Then DCL to delete them: : > $LTOP: > $ READ/END=LEND IFILE IREC > $ DEL/LOG 'IREC' Het middle is erger dan de kwaal? Speaking of wasteful... what about that image activation for each delete. Yikes! I published a simple DCL script for reverse delete a few time in the past. For example in: http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=625667 It combines a few deletes per image activation. These days I'd use PERL: $ perl -le "foreach (reverse sort glob q(test*.*;1)){ print; unlink }" Looks tight, is faster. Cheers, Hein. ------------------------------ Date: 18 Oct 2007 07:54:34 -0500 From: koehler@eisner.nospam.encompasserve.org (Bob Koehler) Subject: Re: Which delete statement is faster? Message-ID: In article , JF Mezei writes: > Have you considered renaming the files needing to be deleted to a > different directory, and then deleting them in that directory where the > size will be more manageable ? > I would think that a rename removing a file from a directory would have the same issues processing the directory file that delete has. set file/enter doesn't have that problem, but deleting the alias does not delete the file, so it also doesn't accomplish anything. ------------------------------ Date: 18 Oct 2007 08:24:21 -0500 From: briggs@encompasserve.org Subject: Re: Which delete statement is faster? Message-ID: In article , JF Mezei writes: > Have you considered renaming the files needing to be deleted to a > different directory, and then deleting them in that directory where the > size will be more manageable ? Alas, that approach doesn't help at all. The problem at hand was that the directory was populated with 200,000 files and the original poster needed to delete the first 30,000 of these. Whether you delete those files or rename them to another directory you still end up removing their directory entries. That leaves you with empty blocks at the front end of a 200,000 file directory. And that means that you need to shift the remaining data down to fill in the vacated blocks. If one was absolutely determined to use such an approach, it would be possible to use a scheme in which _all_ the files are renamed to another directory in reverse alphabetical order and the file names themselves are inverted in lexicographic order -- e.g. A becomes Z, B becomes Y, etc. That way you'd be updating both directories at the tail end. > Also, > > delete az*.*;* > delete ay*.*;* > delete ax*.*;* > ... > delete ac*.*;* > delete ab*.*;* > delete aa*.*;* > > would be faster since it would begin the deletes further down the list > and while not a full "reverse order" delete, it would reduce the amount > of shuffling it needs to do for each delete. If you're deleting the first 30,000 files from a 200,000 file directory, any such optimization can only shave something like 8% off your total elapsed time. You can save yourself from shuffling the first 29,999 directory entries (average 15,000) down, but there are still 170,000 that you can't do anything about with this scheme. ------------------------------ Date: Thu, 18 Oct 2007 14:00:54 -0000 From: Hein RMS van den Heuvel Subject: Re: Which delete statement is faster? Message-ID: <1192716054.941230.256320@q3g2000prf.googlegroups.com> On Oct 16, 3:58 pm, Hein RMS van den Heuvel wrote: > On Oct 16, 3:23 pm, "Mike Minor" wrote: > > > I have a directory with 200000+files, all in the a*.txt;1 range. I need to : > The problem is somewhat similar to one discussed in: > > http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=... > > You may want to check out my rename suggestion there. > It does a double rename to allow the system to allways take from and > add to the end. Actually.... I seem to have posted an intermediate version. Almost right, but not taking from the end towards forwards. Which was the whole point! Ooops Here is the correct example It's just an example, with soem debugging lines still there to help understand it. Adapt to individual needs and perl quirks trying to help with files and filenames. Or re-write to something similar in DCL. use strict; #use warnings; my $HELPER = "[-.tmp_helper]"; my $TARGET = "[-.tmp_renamed]"; my $i = 0; my @files; $_ = shift or die "Please provid double quoted wildcard filespec"; print "wild: $_\n"; s/"//g; my $wild = $_; foreach (qx(DIRECTORY/COLU=1 $wild)) { chomp; $files[$i++] = $_ if /;/; } die "Please provide double quoted wildcard filespec" if @files < 2; # phase 1 $i = @files; print "Moving $i files to $HELPER\n"; while ($i-- > 0) { my $name = $files[$i]; my $new = sprintf("%s%06d%s",$HELPER,999999-$i,$name); print "$name --> $new\n"; rename $name, $new; } system ("DIRECTORY $HELPER"); # phase 2 print "Renaming from $HELPER to $TARGET...\n"; while ($i++ < @files) { my $name = $files[$i]; rename sprintf("%s%06d%s",$HELPER,999999-$i,$name), $TARGET.$name; } Hope this help better :-) Hein. ------------------------------ Date: Thu, 18 Oct 2007 10:45:25 -0500 From: Ron Johnson Subject: Re: Which delete statement is faster? Message-ID: On 10/18/07 06:55, Hein RMS van den Heuvel wrote: > On Oct 18, 3:47 am, Ron Johnson wrote: >> On 10/18/07 01:00, Rudolf Wingert wrote: >> >>> Hello, >>> I think, that the fastest delete is the following: >>> BACKUP/DELETE A*.*;* NL:T/SAVE/NOCRC/GROUP=0 >>> AFAIK this will do all what you want in the right way (reverse order of >>> delete). >> But it wastes so much CPU & IO reading thru all the files. >> >> $ PIPE DIRE/COL=1/NOHEAD/NOTRAIL DISK$FOO:[BAR]*.* | - >> SORT/KEY=(POS:1,SIZE:,DESC) SYS$PIPE FOO_BAR.TXT >> Then DCL to delete them: > : >> $LTOP: >> $ READ/END=LEND IFILE IREC >> $ DEL/LOG 'IREC' > > Het middle is erger dan de kwaal? > > Speaking of wasteful... what about that image activation for each > delete. Yikes! Good point. Then read 3-4 records, concatenating them into one larger string and then delete that. Damn DCL for having in 2007 a 240 byte max record size! > I published a simple DCL script for reverse delete a few time in the > past. > For example in: > http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=625667 > It combines a few deletes per image activation. > > These days I'd use PERL: > > $ perl -le "foreach (reverse sort glob q(test*.*;1)){ print; unlink }" Interesting. > Looks tight, is faster. > > Cheers, -- Ron Johnson, Jr. Jefferson LA USA Give a man a fish, and he eats for a day. Hit him with a fish, and he goes away for good! ------------------------------ Date: 18 Oct 2007 07:56:58 -0500 From: koehler@eisner.nospam.encompasserve.org (Bob Koehler) Subject: Re: WOT: (wildly off-topic) Re: Norway - Europe now calls for kindergarden Message-ID: In article <833a0$4716b932$cef8887a$16960@TEKSAVVY.COM>, JF Mezei writes: > > Except in highly religious families where the kids do not think about > sex until the day they get married. Any human that doesn't think anbout sex before marriage is brain dead, or fairly close to it. ------------------------------ End of INFO-VAX 2007.570 ************************