RE: Hashing Algorithm
If it's classed as a trade secret, then IBM will have to prove they took all reasonable measures to keep it secret. If it was taught to people on the internals course and those people weren't asked to sign an NDA, then bang goes its secret status. And that includes all the people who went on courses run by Informix, Ardent, VMARK et al... Cheers, Wol -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: 14 February 2004 15:46 To: [EMAIL PROTECTED] Subject: Re: Hashing Algorithm In a message dated 2/13/2004 6:18:30 AM Pacific Standard Time, [EMAIL PROTECTED] writes: I have the algorithms (from a legal source long before IBM acquired the product) but because they are now secret I cannot divulge the details. They are, however, extremely simple except for the dynamic algortihms which are rather more exciting. That's a interesting question. I have to say that in general IMHO a company cannot retroactively seize control of something that at one time was freely available. Something in the US about seizure without a warrant? Bill of rights or something? Will I'm not a lawyer, but I play one on the Internet Johnson -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users *** This transmission is intended for the named recipient only. It may contain private and confidential information. If this has come to you in error you must not act on anything disclosed in it, nor must you copy it, modify it, disseminate it in any way, or show it to anyone. Please e-mail the sender to inform us of the transmission error or telephone ECA International immediately and delete the e-mail from your information system. Telephone numbers for ECA International offices are: Sydney +61 (0)2 9911 7799, Hong Kong + 852 2121 2388, London +44 (0)20 7351 5000 and New York +1 212 582 2333. *** -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
In a message dated 2/13/2004 6:18:30 AM Pacific Standard Time, [EMAIL PROTECTED] writes: I have the algorithms (from a legal source long before IBM acquired the product) but because they are now secret I cannot divulge the details. They are, however, extremely simple except for the dynamic algortihms which are rather more exciting. That's a interesting question. I have to say that in general IMHO a company cannot retroactively seize control of something that at one time was freely available. Something in the US about seizure without a warrant? Bill of rights or something? Will I'm not a lawyer, but I play one on the Internet Johnson -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
It might be interesting if someone were to publish the Ardent hashing algorithms, then. ;) Not something I'm prepared to risk doing, however. - Original Message - From: [EMAIL PROTECTED] Date: Sat, 14 Feb 2004 10:45:45 EST To: [EMAIL PROTECTED] Subject: Re: Hashing Algorithm I have to say that in general IMHO a company cannot retroactively seize control of something that at one time was freely available. Something in the US about seizure without a warrant? Bill of rights or something? Will I'm not a lawyer, but I play one on the Internet Johnson -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
Is that one similiar to the 'only' one available to native systems, which many people have known for years? - Original Message - From: Ray Wurlod [EMAIL PROTECTED] To: U2 Users Discussion List [EMAIL PROTECTED] Sent: Saturday, February 14, 2004 5:06 PM Subject: Re: Hashing Algorithm It might be interesting if someone were to publish the Ardent hashing algorithms, then. ;) Not something I'm prepared to risk doing, however. - Original Message - From: [EMAIL PROTECTED] Date: Sat, 14 Feb 2004 10:45:45 EST To: [EMAIL PROTECTED] Subject: Re: Hashing Algorithm I have to say that in general IMHO a company cannot retroactively seize control of something that at one time was freely available. Something in the US about seizure without a warrant? Bill of rights or something? Will I'm not a lawyer, but I play one on the Internet Johnson -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
It's not one, it's all 19 of them (types 2 through 18 and two for type 30). The Type 18 algorithm is closest to the Pick hashing algorithm. - Original Message - From: Mark Johnson [EMAIL PROTECTED] Date: Sat, 14 Feb 2004 18:00:26 -0500 To: U2 Users Discussion List [EMAIL PROTECTED] Subject: Re: Hashing Algorithm Is that one similiar to the 'only' one available to native systems, which many people have known for years? -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: Hashing Algorithm
Could anyone let me know where can I found information about the way the Hash Algorithm Works with each one of the File Types in UniVerse? It does, of course, lead to the question of why you want to know! Why not? .. I'd bet on simple (or not so simple) curiousity .. Aren't we all pretty much tech geeks here? .. Maybe he wants to see the hashing mathematics for himself and then check out a high speed data structures book and see if they're all they're cracked up to be .. -Chuck -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
Why not? .. I'd bet on simple (or not so simple) curiousity .. Aren't we all pretty much tech geeks here? .. Maybe he wants to see the hashing mathematics for himself and then check out a high speed data structures book and see if they're all they're cracked up to be .. I have the algorithms (from a legal source long before IBM acquired the product) but because they are now secret I cannot divulge the details. They are, however, extremely simple except for the dynamic algortihms which are rather more exciting. Martin Phillips Ladybridge Systems 17b Coldstream Lane, Hardingstone, Northampton NN4 6DB +44-(0)1604-709200 -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: Hashing Algorithm
[EMAIL PROTECTED] 02/13/2004 8:49:08 AM Could anyone let me know where can I found information about the way the Hash Algorithm Works with each one of the File Types in UniVerse? It does, of course, lead to the question of why you want to know! Would knowing the algorithms allow you to write a program that would accept parameters about your file, or even walk the file, to determine which file type would be best for that file? Karjala -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
From: Karjala Koponen [EMAIL PROTECTED] Would knowing the algorithms allow you to write a program that would accept parameters about your file, or even walk the file, to determine which file type would be best for that file? Years ago I wrote a FTN program that analyzed PR1ME INFORMATION files and recommended file types and modulos. Problem with it was that it required a reasonably in-depth understanding of the data structures, and they changed in some releases. When HASH.HELP became robust enough I quit using my program as I couldn't justify the development time/effort. Instead I wrote a front-end which generated paragraphs consisting primarily of HASH.HELP %filename% statements. The paragraphs included COMO statements, and the final statement ran a program to interpret the output from the HASH.HELP and execute an appropriate RESIZE command. -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: Hashing Algorithm
It does, of course, lead to the question of why you want to know! I used to have a program I calledthat would take a select list sort it according to the group order of the file it was going to be applied to. For really big lists it made a really big difference because subsequent file i/o flowed sequentially through the file with several consecutive groups read into memory by the os, (yes, except for overflow) then all records from those groups processed. I would use it whenever I had a big select list that was built independently of the file it was going to process and the processing order did not really matter. It worked on Pick, where their one algorithm is well-know and easily duplicated, and on Prime, which gave us the !HASHID function. (I think that's what it was called, but I may be remembering !HUSHIT, which my dyslexic brain would always turn around, sticking the ! on the back end and associating the SH with the IT that followed instead of with the preceding HU, which dyslexia somehow converted into OH, anyway.) I wouldn't care about their algorithms, per se, but I wish IBM would give us a similar function: GROUP.NO = HASHID( TYPE, MOD, SEP, ID ) Sort of like the RECORD verb, except that actually goes out and does file i/o: RECORD VOC ASDASDF Record ASDASDF hashes to group 233 but was not found. RECORD VOC SYS.HELP Record SYS.HELP hashes to group 847 and was found. -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
Re: Hashing Algorithm
When HASH.HELP became robust enough I quit using my program as I couldn't justify the development time/effort. Instead I wrote a front-end which generated paragraphs consisting primarily of HASH.HELP %filename% statements. The paragraphs included COMO statements, and the final statement ran a program to interpret the output from the HASH.HELP and execute an appropriate RESIZE command. Many users do this. But beware that HASH.HELP is not perfect. There is one bug, for example, that we exploit in an example in the UK UniVerse training courses, where HASH.HELP gets it hopelessly wrong but which is easy to fix by hand. Personally, I am a great believer in dynamic files. About five years ago I did a migration from PI/open to UniVerse for a site with over 13000 files. There was absolutely no way that I was going to do file calculations for all of those so I made the lot dynamic and said that I would tune up any that presented performance problems. I visited the site last week. They are still overjoyed with performance, have spent absolutely NO time on file tuning, and have experienced no problems with these files. Of course, I have lost a good source of income providing a regular file tuning service! Martin Phillips Ladybridge Systems 17b Coldstream Lane, Hardingstone, Northampton NN4 6DB +44-(0)1604-709200 -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: Hashing Algorithm
I used to have a program I calledthat would take a select list sort it according to the group order of the file it was going to be applied to. For really big lists it made a really big difference What a great idea! I wish IBM would give us a similar function On UniData you can use the UniBasic HASH function to get the group a record would hash to, without performing any I/O. Just supply the key, modulo, and file type. Tim Snyder IBM Data Management Solutions Consulting I/T Specialist , U2 Professional Services Office (717) 545-6403 (rolls to cell phone) [EMAIL PROTECTED] -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: Hashing Algorithm
Exactly, I want to know the calculations of the algorithm for each file type to determine which file type is the best for any file. -Mensaje original- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] En nombre de Karjala Koponen Enviado el: viernes, 13 de febrero de 2004 8:48 Para: [EMAIL PROTECTED] Asunto: RE: Hashing Algorithm [EMAIL PROTECTED] 02/13/2004 8:49:08 AM Could anyone let me know where can I found information about the way the Hash Algorithm Works with each one of the File Types in UniVerse? It does, of course, lead to the question of why you want to know! Would knowing the algorithms allow you to write a program that would accept parameters about your file, or even walk the file, to determine which file type would be best for that file? Karjala -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
