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Re: [Alug] ALUG Librarian stuff
by MJ Ray 10 Jun '01

10 Jun '01

David Freeman <david_freeman(a)rocketmail.com> writes: > This is cos you probalby have no formal training in systems analysis. > once you try and use them they will become second nature, have a look > at the book "UML in a nutshell" it explains it all, I was like you I > ignored it all untill I understood how it would all work, I now will > try and use UML for my software to improve it. Well, I'll take a look, but the majority of systems analysis methods appeared to be focused on the object-orientated imperative paradigm, which isn't where I usually (want to) live. Am I wrong on this? Would I be able to use UML in my work? I know that I've been on panels rejecting a candidate who started spouting about using UML. (OK, they were also talking about Z, formally proving programs and other things we didn't want for a "data juggler" who had to start with a backlog of data which had already had its format designed by experts elsewhere ;-) ) > > http://rabbit.stu.uea.ac.uk/pipermail/alug/2001-May/001083.html > > Only Brett seemed to criticise it... > Critisie my scheme or my methods? Scheme afaict. > > > Good code is code which meets the needs of the application and > > > doesn't crash. [...] > > Being written is a prerequisite for these. > No its not, being written well is the prerequisite. How is being written not a prereq for being written well? ;-) > > Is an RDBMS appropriate, or should we just assume an OO backing > > store? > true, but the principles are the same, they all boil down to designing > a relationa scheme which then needs to be normalised, and as relational > theory is based on set theory as is OO theory the design is applicable > to both, hence my keeping animplementation independent view of things. The realities of modern RDBMSs with all the triggers and code inside the database seems to be quite far from pure set theory to me. There's quite a nice piece about it in the most recent VSJ, I think. -- MJR

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Re: [Alug] ALUG Librarian stuff
by MJ Ray 10 Jun '01

10 Jun '01

David Freeman <david_freeman(a)rocketmail.com> writes: > I never got around to ripping it a part. The problems are > 1) Based on assumptions > a) People are honest Have to pretty much try this. Having some sort of deposits may be a good move, but who holds them? > b) People will notice books have gone astray Send out "please confirm your borrowing" emails and email the maintainers or this list if people don't answer? > c) People will return books Same as a, surely? > In that case you haven't modelled the system properly. You can't start > programming till you have a decent enough idea of how it will work. > incedentally I will have a modell created by mondays IRC. It seems this model is slipping further and further back... > There needs to be a dead line for collection and for loans, but you > would have modelled this in the functional requirements. Unless we discuss this thing, how do we find these things out? I don't believe any initial model will get all of these things right first time. > And what are assumptions? Assumptions are beliefs which you accept as truths in order to build a logical system. They cannot be proved, but they are used to prove other results. I would have thought you'd know that, having used the word so freely... -- MJR

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Re: [Alug] ALUG Librarian stuff
by brodders＠cwcom.net 10 Jun '01

10 Jun '01

Hi David! ----- Original Message ----- From: "David Freeman" <david_freeman(a)rocketmail.com> To: <alug(a)stu.uea.ac.uk> Sent: Saturday, June 09, 2001 10:22 PM Subject: Re: [Alug] ALUG Librarian stuff > > --- brodders(a)cwcom.net wrote: > > > > Migod! ALUG Library's...come back to life! > > My<insert object of worship here (Linux torvolds, RMS, ESR, Steve Jobs, > sarah michelle gella etc...)> it has come back to life, RUN! :) poor poor linus .. like it! > > OK so no-ones ripped a new one in the idea of a peer-peer ALUG > > Library. That's > > nice; I assumed we'd go that way so I've quietly been doodling > > around with > > the concepts. > > I never got around to ripping it a part. The problems are > > 1) Based on assumptions > a) People are honest > b) People will notice books have gone astray > c) People will return books yes. It's either that or it gets real difficult. Seriously, casual fraud is the only real threat if people try to use the system at all, the system will know who's got what. From this stocktake data is available. The threat is that people just ignore the system, pass things around & it collapses into one big muddle. I don't know how we can stop this one. > > Have not thought about consequences of wandering people; don't think > > it's too > > much of a problem insofar it's generic & will not go away. I'm for > > doing no > > more than normal add-person, delete/edit person etc. Um? fine person? > > New joiners > > give a sub which they get back when they go LESS losses? Could be > > expensive. > > Perhaps a borrowing cap is in order. Another table... NOPE a new > > attributes > > of the Person table; default say 4. > > In that case you haven't modelled the system properly. You can't start > programming till you have a decent enough idea of how it will work. > > incedentally I will have a modell created by mondays IRC. excellent. Will it have pictures? I like pictures. > > This might as well be a progress report on what I've done, so here > > goes. > > > > Top level concepts as last reported + thoughts on this issue: > > > > Are there any issues if item passed to wrong person. Example: > > Person A has WonderBook which everyone wants. Person's B,C,D etc. > > request it. > > B is at top of list. > > Yes. What happens to person B and C do they still remain at places 1 > and 2 in the list? What if they ask for the book to be mailed to them? > > > At the next meet everyone is there except B. Oh dear - a ruck forms; > > A & book > > disappear from view & when tussle clears D has made off with it. > > "Well, B had > > their chance." > > See above. > > > Is this legal? Don't see why not; B could well miss a meet & it seems > > fine to > > me that someone else gets the book. For this to work, everyone must > > have been > > issued a key to give A. That may mean another table for the > > confirmation keys > > rather then finding a home for <the one key> in say the Transaction > > table. > > There needs to be a dead line for collection and for loans, but you > would have modelled this in the functional requirements. > Why? This is at heart a stock control system, in the guise of stock tracking. If an item stays on a shelf for a month, does it need permission to stay there for another month? Is there actually a need to have controlled returns if we know where the item is? We do not have to model our system on anyone else's ideas of how libraries work. > > Alternatively if it's NOT OK to passover B - what then? Perhaps C > > only should > > be allowed to have the book, not D as decided in the tussle? > > Let me think on this one. > > > My instinct is that the more flexible the better; so I'd plump for > > "issue N > > confirmation keys & let people decide for themselves". There are more > > arguments > > around this area (the confirmation key is now effectively a person > > ID, so why > > keep on scrambling it?) but overall I'm happy with this. It's more > > secure / > > difficult to defraud this way. > > see above comment > Ultimately - to be perfect the complexity of the solution must mirror the complexity inherent in the problem domain. Or, lop off minor complexities / degrees of freedom in the problem deliberately to straightjacket (= simplify) the solution. I actually sent myself to sleep a few weeks ago thinking about issues arising from trying to correct out-of-order borrowing & impacts on issued keys. Danger Will Robinson - don't go there! Let's make it simple. > > Next up, db progress. > > > > Postgres is wonderful, BUT as I had everything to hand to get going > > with MySQL > > so I made a start using it (also I had another project which used > > MySQL). > > Fine any DBMS should do the job, even access should work, if designed > properly. > > > Now when I make a start I explore problem areas. This ties in with my > > design > > assumptions - which are that everything's easy - except for the > > problems. So > > I want to know - what are the problems & where are they? Once these > > are conquered > > I can go back to sleep (=base mode). > > And what are assumptions? That everything is easy apart from the difficult bits. And, where it ain't easy, I hits it with this here hammer until it gets simple :) What I'm saying is that people can make things work - if the things are possible to work at all. So, explore what's more possible vs. what's less (or im)possible. This is based on a top-down development view which says "don't rely on things which can't be made to work". Idea is to identify the easy / practical route; this means proof-of-concept tests needed when going into new areas. Once a solution strategy is found possible, getting it working is through dint of effort; leg-work if you will. That's what the next bit is about - I needed a way of proving the solution strategy. > > > First up I needed a model environment, so I put together a box > > networked to > > a PC. There's the server, here's the client <this included a big > > diversion fighting > > various Linux distros; they didn't like the ancient embedded video on > > the server>. > > MySQL goes in, fight with that. Many minor mistakes; finally import a > > test database > > - for the other project; but principles established. Install MyODBC > > onto the > > PC; that is a success. > > sounds like the usual linux development problems. :) > > Next up - how to actually do it? I want a RAD or sumfin'. > > How about doing it the real way and telneting in and using SQL? yep that works too; 's how I did the import & initial table setup etc. > > Access works well via the ODBC, but that's not PC. Hm. StarOffice > > 5.2! It sort > > of works and crashes but it's just about usable; snag it it doesn't > > quite fit > > MySQL nicely. > > hmmm? Subtle unhappynesses which seem to be connected with.. SO5.2 doesn't like base data types used by MySQL, strikes attitudes about keys, crashes when it feels like. Teeters on usable; often just pulls a trick. The MyODBC drivers seem fine with SO though. I can fix table layout shenanigans using SQL.. & my hammer awaits if it needs it's mind changed. > > At this point I was going to make a start putting some default forms > > together. > > OK not for the final system; they'll have to be over the web. But > > these are > > 1st shot functional screens to get things going; SO5.2 has a GUI > > editor all > > drag'n'dropish with predefined stuff (fields, buttons, pull down > > lists etc) > > & that's nice esp. when it accesses the remote test MySQL db and I > > see real > > data in the fields on my PC. At that point I went on holiday & now > > it's now. > > Have you defined the queries necessary to support the application? In SQL, no, but have worked up notes giving the expectations (delivered functionality) for these. Mostly they are obvious add/delete/edit for the main tables apart from reports & the tricky bits most tricky being the transaction models for requesting & borrowing. That's why I raise the issues re librarian/peer-peer; these are key process assumptions. Also don't forget the need to stocktake and do a check on integrity. Stocktake can be done on the fly, ie when an item goes through the hands of a trusted party the item can be "audited". Another table becons. I imagine the integrity check to er um prove transactions are ordered OK vs datestamp sequence, run through transactions and prove the items / persons etc tie in and make sense. Thanks! Steve > > > Be Warned - I'm not a coder (well not in the last 15 years). > > Neither am I nor am I a Systems analyis, but I think as a group we will > muddle through > > Thanks > > D > > > Bye Bye for now! > > > > Steve > > > > > > > > > > _______________________________________________ > > alug, the Anglian Linux User Group list > > Send list replies to alug(a)stu.uea.ac.uk > > http://www.anglian.lug.org.uk/ > > http://rabbit.stu.uea.ac.uk/cgi-bin/listinfo/alug > > See the website for instructions on digest or unsub! > > > __________________________________________________ > Do You Yahoo!? > Get personalized email addresses from Yahoo! Mail - only $35 > a year! http://personal.mail.yahoo.com/ > > > _______________________________________________ > alug, the Anglian Linux User Group list > Send list replies to alug(a)stu.uea.ac.uk > http://www.anglian.lug.org.uk/ http://rabbit.stu.uea.ac.uk/cgi-bin/listinfo/alug > See the website for instructions on digest or unsub!

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Re: [Alug] Meeting poster
by MJ Ray 10 Jun '01

10 Jun '01

Neill Newman <neill(a)entora.co.uk> writes: > any parking available ?? also some basic directions might be nice ;) Yes. I'll add the actual venue info URL to it. -- MJR

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Meeting poster
by MJ Ray 10 Jun '01

10 Jun '01

Postscript of a poster is available from my web site at http://www.towers.org.uk/alug/poster2001-6.ps.gz Please use it. The proper announcement will follow as soon as I've got control (or at least figured out why I don't have control) of the web site. -- MJR

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Re: [Alug] ALUG Librarian stuff
by brodders＠cwcom.net 10 Jun '01

10 Jun '01

Migod! ALUG Library's...come back to life! OK so no-ones ripped a new one in the idea of a peer-peer ALUG Library. That's nice; I assumed we'd go that way so I've quietly been doodling around with the concepts. Have not thought about consequences of wandering people; don't think it's too much of a problem insofar it's generic & will not go away. I'm for doing no more than normal add-person, delete/edit person etc. Um? fine person? New joiners give a sub which they get back when they go LESS losses? Could be expensive. Perhaps a borrowing cap is in order. Another table... NOPE a new attributes of the Person table; default say 4. This might as well be a progress report on what I've done, so here goes. Top level concepts as last reported + thoughts on this issue: Are there any issues if item passed to wrong person. Example: Person A has WonderBook which everyone wants. Person's B,C,D etc. request it. B is at top of list. At the next meet everyone is there except B. Oh dear a ruck forms; A & book disappear from view & when tussle clears D has made off with it. "Well, B had their chance." Is this legal? Don't see why not; B could well miss a meet & it seems fine to me that someone else gets the book. For this to work, everyone must have been issued a key to give A. That may mean another table for the confirmation keys rather then finding a home for <the one key> in say the Transaction table. Alternatively if it's NOT OK to passover B what then? Perhaps C only should be allowed to have the book, not D as decided in the tussle? My instinct is that the more flexible the better; so I'd plump for "issue N confirmation keys & let people decide for themselves". There are more arguments around this area (the confirmation key is now effectively a person ID, so why keep on scrambling it?) but overall I'm happy with this. It's more secure / difficult to defraud this way. Next up, db progress. Postgres is wonderful, BUT as I had everything to hand to get going with MySQL so I made a start using it (also I had another project which used MySQL). Now when I make a start I explore problem areas. This ties in with my design assumptions which are that everything's easy - except for the problems. So I want to know what are the problems & where are they? Once these are conquered I can go back to sleep (=base mode). First up I needed a model environment, so I put together a box networked to a PC. There's the server, here's the client <this included a big diversion fighting various Linux distros; they didn't like the ancient embedded video on the server>. MySQL goes in, fight with that. Many minor mistakes; finally import a test database for the other project; but principles established. Install MyODBC onto the PC; that is a success. Next up how to actually do it? I want a RAD or sumfin'. Access works well via the ODBC, but that's not PC. Hm. StarOffice 5.2! It sort of works and crashes but it's just about usable; snag it it doesn't quite fit MySQL nicely. At this point I was going to make a start putting some default forms together. OK not for the final system; they'll have to be over the web. But these are 1st shot functional screens to get things going; SO5.2 has a GUI editor all drag'n'dropish with predefined stuff (fields, buttons, pull down lists etc) & that's nice esp. when it accesses the remote test MySQL db and I see real data in the fields on my PC. At that point I went on holiday & now it's now. Be Warned I'm not a coder (well not in the last 15 years). Bye Bye for now! Steve

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Re: [Alug] ALUG Librarian stuff
by MJ Ray 09 Jun '01

09 Jun '01

David Freeman <david_freeman(a)rocketmail.com> writes: > No somebody who has learnt the hardway that you need to design the > code, if nothing else to design the bugs out. I'm not ont for creating > BIG designs etc... just nice highlevel concept diagrams and other > USEFUL things like that. Yeah, pretty pictures. Everyone likes pretty pictures. 'cept me. I'll take a good explanation over a specialised diagram requiring a key almost any time. > How can you say that? I originally posted a relational scheme to the > list and was told tht it was naive and was lacking and some other > scheme were posted, had we designed it correctly we would have the > scheme ok first time round. http://rabbit.stu.uea.ac.uk/pipermail/alug/2001-May/001083.html Only Brett seemed to criticise it... > [...] What we must avoid like the plague is making assumptions, any > engineer ot scientist will tell you that an assumption is the mother > of all f*** ups. What am I? A pomegranate? > Good code is code which meets the needs of the application and > doesn't crash. [...] Being written is a prerequisite for these. > Good. For now we need to just assume we have a RDBMS until the point > when we have the design done. Is an RDBMS appropriate, or should we just assume an OO backing store? -- MJR

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Re: [Alug] ALUG Librarian stuff
by MJ Ray 09 Jun '01

09 Jun '01

David Freeman <david_freeman(a)rocketmail.com> writes: > [...] We are analysing a system here and we need to maintain an > implementation specific view of things until we get into the design > stage. As I can see things, we skipped the feasibilty stage and also > the analysis and Design stages, and thus we have arrived at the > implementation phase with some major lack of designs. ARRRRRRRRRRGH -- another "big design" fan? Do the phrases "you aren't gonna need it" and "do the simplest thing that could possibly work" mean anything to you? http://c2.com/cgi/wiki?ExtremeProgrammingRoadmap I mean, yes, let's design this thing, and the start of this thread is a good starting point, but let's not waste time procrastinating and drawing pretty pictures of the system. Good code is written code, before anything else. > [...] Can we get anything on the alug.org.uk hosts in the way > of either mysql or postgres? I don't know, but I'd expect so, or at least a hostname pointed somewhere that did. -- MJR

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[alt.uu.comp.os.linux.questions] Recommended Linux Reference Books??
by MJ Ray 09 Jun '01

09 Jun '01

Here's a thread from elsewhere about something we discussed... ---------------------------------------------------------------------- Date: Thu, 07 Jun 2001 21:49:41 GMT From: "X_Factor6" <m.tiesman(a)home.com> Subject: Recommended Linux Reference Books?? Message-ID: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> what are some good reference books for Linux?? I already have a couple from O'reilly & Associates. Let me know Thanks. X_Factor6 ------------------------------ Date: Fri, 8 Jun 2001 03:04:28 +0200 From: "R.V. Gronoff" <regis.gronoff(a)laposte.net> Subject: Re: Recommended Linux Reference Books?? Message-ID: <9fp951$5af5t$1(a)ID-77205.news.dfncis.de> References: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> "Linux Essential Reference", by Raymond Debonne ------------------------------ Date: Fri, 08 Jun 2001 08:13:53 GMT From: jayfar(a)netaxs.com (Jayfar) Subject: Re: Recommended Linux Reference Books?? Message-ID: <slrn9i12a0.44s.jayfar(a)access.netaxs.com> References: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> I'm looking at a cow-orker's copy of "Linux - The Complete Reference," 4th edition (2001), by Richard Peterson, which includes info on 2.4 kernel. It's from Osborne, ISBN #0-07-212940-9 and weighs in at a hefty 1200+ pages. Jayfar - - Netaxs Network Operations Center ------------------------------ Date: Fri, 08 Jun 2001 08:26:27 -0500 From: David Douthitt <ssrat(a)mailbag.com> Subject: Re: Recommended Linux Reference Books?? Message-ID: <3B20D283.703E5F3D(a)mailbag.com> References: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To me, every UNIX administrator and every UNIX power user should have the following book: * "UNIX in a Nutshell", by Daniel Gilley and the staff of O'Reilly & Assoc. You didn't say what sort of books you wanted: * Technical? * Programming? * Administration? * Introductory? However, I would recommend the "....Unleashed" series - like "Linux Unleashed" and "Red Hat Linux Unleashed." Also likely a good source is "Running Linux" published by O'Reilly. Also, when you go looking at books, don't just look at Linux books, but also at generic UNIX books - stay away from version specific books (like Unixware or Solaris or HP-UX) - they all have their differences. ------------------------------ Date: Fri, 8 Jun 2001 15:22:33 +0100 From: SteveCampbell <the.goonden(a)ntlspamworld.com> Subject: Re: Recommended Linux Reference Books?? Message-ID: <La5U6.19288$YB3.2950923(a)news2-win.server.ntlworld.com> References: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit the best and most relevant docs are on your system ot at www.linuxdoc.org having said that, you are probably like me and much prefer printed stuff you can relax with over a coffee. Just remember that other source of info as it is invaluable. ------------------------------ Date: Fri, 08 Jun 2001 16:15:01 -0000 From: rodsmith(a)speaker.rodsbooks.com (Rod Smith) Subject: Re: Recommended Linux Reference Books?? Message-ID: <ti1ug55cl3dn39(a)corp.supernews.com> References: <VFST6.30136$Q9.6942135(a)news1.elmhst1.il.home.com> Content-Type: text/plain; charset=us-ascii The field of Linux books is pretty broad. There are tutorial books, reference books, etc.; and these cover Linux generally, Linux networking, Linux programming, etc., as well as sub-sets of these (like books on specific servers). I've got a Web page with suggestions in several categories at http://www.rodsbooks.com/books/. (That page features my own books, so I can't claim to be an unbiased source of information. ;-) Sub-pages include some suggestions on books by others, though.) - - Rod Smith, rodsmith(a)rodsbooks.com http://www.rodsbooks.com Author of books on Linux & multi-OS configuration ------------------------------ End of Digest ************* -- MJR Member of the Anglian Linux User Group, UK Meets every month or so and OPN #alug on Mondays at 2000 UK http://www.anglian.lug.org.uk/

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Re: [Alug] Pingful success at last!
by MJ Ray 09 Jun '01

09 Jun '01

David Freeman <david_freeman(a)rocketmail.com> writes: > Perhaps a more detailed account of what was wrong and how it was fixed > could go on the web so that others who have this problem can get it > fixed. Email it to me. It may motivate me to fix the repository and bring the site up to date. -- MJR

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