COBOL "non-myth" confirmed - Index and subscripts (MF on Windows)
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From: Pete Dashwood on 17 Sep 2007 22:19 "Charles Hottel" <chottel(a)earthlink.net> wrote in message news:13eu3serlerr449(a)corp.supernews.com... > > "Howard Brazee" <howard(a)brazee.net> wrote in message > news:pabte318v4n344saoq74ifeh7u3t1f8v9n(a)4ax.com... >> On Sat, 15 Sep 2007 01:50:53 -0500, Robert <no(a)e.mail> wrote: >> >>>Most people who use indexes believe it. Why else would they use indexes? >> >> Habit. > > When was the last time anyone posting here ever had a performance problem > whose solution was related to subscripting or indexing? Changing to > indexes in order to do a binary search being excluded. The few times that > I have had to optimize generally involved changing to a better algorithm. > One program on a 360/30 took over two hours. I changed it to use two > 8000 byte buffers (that was the largest I could make them due to storage > constraints) and the time dropped to 10 to 15 minutes. I have changed > sequential sorts to binary sort both hand coded using subscripts and using > SEARCH ALL. The hand coded subscript approach avoided searching any table > entries that have not been loaded with data just by proper setting of the > HI subscript. Although as Pete and other here have posted I don't recall > ever having that problem. Much later on I had to optimize a couple of > programs that were slow due to high volume random access of VSAM KSDS > files. The solution was to sort the input transactions which took away a > lot of the randomness and effectively resulting in cacheing where > subsequent transaction could take advantage of data already read by the > previous transaction. I have not had a performance problem of any type in > the last 20 years. > Good post, re-establishing some perspective here...:-) > I suggest we move on to another more interesting thread, perhaps one where > two fleas argue over which one owns the dog that they live on. Two fleas hop out of a theatre. One says to the other: "Shall we walk home or catch a dog?" Pete. -- "I used to write COBOL...now I can do anything."
From: LX-i on 17 Sep 2007 23:45 Robert wrote: > > Most people who use indexes believe [they are faster]. Why else would they use indexes? I used indexes because I liked the way that they kept a table and its pointer unified. I've also used indexes on large text-accruing tables. I like the way they look. (And, I proved that they're a lot faster than reference modification...) -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ / \/ _ o ~ Live from Albuquerque, NM! ~ ~ _ /\ | ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Business E-mail ~ daniel @ "Business Website" below ~ ~ Business Website ~ http://www.djs-consulting.com ~ ~ Tech Blog ~ http://www.djs-consulting.com/linux/blog ~ ~ Personal E-mail ~ "Personal Blog" as e-mail address ~ ~ Personal Blog ~ http://daniel.summershome.org ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GEEKCODE 3.12 GCS/IT d s-:+ a C++ L++ E--- W++ N++ o? K- w$ !O M-- V PS+ PE++ Y? !PGP t+ 5? X+ R* tv b+ DI++ D+ G- e h---- r+++ z++++ "Who is more irrational? A man who believes in a God he doesn't see, or a man who's offended by a God he doesn't believe in?" - Brad Stine
From: Charles Hottel on 18 Sep 2007 08:26 "Pete Dashwood" <dashwood(a)removethis.enternet.co.nz> wrote in message news:5l8qsuF70aj9U1(a)mid.individual.net... > > > "Charles Hottel" <chottel(a)earthlink.net> wrote in message > news:13eu3serlerr449(a)corp.supernews.com... >> >> "Howard Brazee" <howard(a)brazee.net> wrote in message >> news:pabte318v4n344saoq74ifeh7u3t1f8v9n(a)4ax.com... >>> On Sat, 15 Sep 2007 01:50:53 -0500, Robert <no(a)e.mail> wrote: >>> >>>>Most people who use indexes believe it. Why else would they use indexes? >>> >>> Habit. >> >> When was the last time anyone posting here ever had a performance problem >> whose solution was related to subscripting or indexing? Changing to >> indexes in order to do a binary search being excluded. The few times that >> I have had to optimize generally involved changing to a better algorithm. >> One program on a 360/30 took over two hours. I changed it to use two >> 8000 byte buffers (that was the largest I could make them due to storage >> constraints) and the time dropped to 10 to 15 minutes. I have changed >> sequential sorts to binary sort both hand coded using subscripts and >> using SEARCH ALL. The hand coded subscript approach avoided searching >> any table entries that have not been loaded with data just by proper >> setting of the HI subscript. Although as Pete and other here have posted >> I don't recall ever having that problem. Much later on I had to optimize >> a couple of programs that were slow due to high volume random access of >> VSAM KSDS files. The solution was to sort the input transactions which >> took away a lot of the randomness and effectively resulting in cacheing >> where subsequent transaction could take advantage of data already read by >> the previous transaction. I have not had a performance problem of any >> type in the last 20 years. >> > > Good post, re-establishing some perspective here...:-) > >> I suggest we move on to another more interesting thread, perhaps one >> where two fleas argue over which one owns the dog that they live on. > > Two fleas hop out of a theatre. > One says to the other: "Shall we walk home or catch a dog?" > > Pete. > -- > "I used to write COBOL...now I can do anything." > LMAO
From: pgx on 18 Sep 2007 11:28 "Charles Hottel" <chottel(a)earthlink.net> wrote: | I have not had a |performance problem of any type in the last 20 years. | Do you pay for the CPU time our of your own pocket? Phil
From: Howard Brazee on 18 Sep 2007 12:38
On Mon, 17 Sep 2007 19:37:40 -0400, "Charles Hottel" <chottel(a)earthlink.net> wrote: >When was the last time anyone posting here ever had a performance problem >whose solution was related to subscripting or indexing? That has never been the solution for me. |