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  4. When normalization goes wrong. Horribly.

When normalization goes wrong. Horribly.

Scheduled Pinned Locked Moved The Weird and The Wonderful
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  • P peterchen

    TheDailyWTF taught me that a "Date" table as such is not uncommon in business applications. Since it's expensive to calculate holidays, business days, etc. they are calculated upfront and put into a date table that aids queries such as "next business day after" (maybe through a trigger when adding a previously unknown date, or through a script generating all dates up to 2015).


    We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
    My first real C# project | Linkify!|FoldWithUs! | sighist

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    Tristan Rhodes
    wrote on last edited by
    #14

    A Date table is daft. An Exclusive set is easier to manage than Inclusive set. Better off having a table with all the holidays in it, and manage the weekend checks in code. But i don't know the caveats. I'm sure dumping every single date from now till the end of time into a table is not an efficient way of doing it.

    ------------------------------- Carrier Bags - 21st Century Tumbleweed.

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    • M martin_hughes

      Andy Brummer wrote:

      You need to fix any such rampant denormalization before you migrate the "database"

      Having spent a couple of hours ruminating, I'm thinking about returing an "unfeasible" on this feasability report :)

      "It was the day before today.... I remember it like it was yesterday." -Moleman

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      Dave Kreskowiak
      wrote on last edited by
      #15

      Have you thought of beginning the report with the phrase "Oh my God! What idiot..."??

      A guide to posting questions on CodeProject[^]
      Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
           2006, 2007

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      • M martin_hughes

        Andy Brummer wrote:

        You need to fix any such rampant denormalization before you migrate the "database"

        Having spent a couple of hours ruminating, I'm thinking about returing an "unfeasible" on this feasability report :)

        "It was the day before today.... I remember it like it was yesterday." -Moleman

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        chrishuff
        wrote on last edited by
        #16

        To bad you can't tell them... "I took it out behind the barn and shot it. Now I'm writing a brand spanking-new database."

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        • T Tristan Rhodes

          A Date table is daft. An Exclusive set is easier to manage than Inclusive set. Better off having a table with all the holidays in it, and manage the weekend checks in code. But i don't know the caveats. I'm sure dumping every single date from now till the end of time into a table is not an efficient way of doing it.

          ------------------------------- Carrier Bags - 21st Century Tumbleweed.

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          PaulPrice
          wrote on last edited by
          #17

          Hell I just rewrote a function I found that was calculating a Spot Date (2 Working days forwrd from the Deal date in FX trading). It worked on an Exclusive set as you say, but instead of getting all of the holidays for the specific currencies (of which there is always 2 and always known in advance) and working with that. It looped adding a day until it did not get a count > 0 from an SQL statement like this and it is a weekday. Select count(CurrencyId) from Holiday Where holidayDate = '2007/01/01' where it changed the date forward. To work out one spot date over the christmas period it would open, query close anything up to 4 or 5 times per confirmation. Crazy I tell ya. You will be pleased to note that it no longer does this ;-)

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          • D Dave Kreskowiak

            Have you thought of beginning the report with the phrase "Oh my God! What idiot..."??

            A guide to posting questions on CodeProject[^]
            Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
                 2006, 2007

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            Paul Conrad
            wrote on last edited by
            #18

            Dave Kreskowiak wrote:

            Have you thought of beginning the report with the phrase "Oh my God! What idiot..."?

            :laugh: I am sure that would go over well with some PHB management wienie..

            "Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

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            • P Paul Conrad

              Dave Kreskowiak wrote:

              Have you thought of beginning the report with the phrase "Oh my God! What idiot..."?

              :laugh: I am sure that would go over well with some PHB management wienie..

              "Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

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              Dave Kreskowiak
              wrote on last edited by
              #19

              Paul Conrad wrote:

              wienie..

              The key word being "wienie". If he/she's a wienie, then they have no sense of humor and I would have to leave the company because of this personal condition, which I find hostile to my own creativity and motivation.

              A guide to posting questions on CodeProject[^]
              Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
                   2006, 2007

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              • D Dave Kreskowiak

                Paul Conrad wrote:

                wienie..

                The key word being "wienie". If he/she's a wienie, then they have no sense of humor and I would have to leave the company because of this personal condition, which I find hostile to my own creativity and motivation.

                A guide to posting questions on CodeProject[^]
                Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
                     2006, 2007

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                Paul Conrad
                wrote on last edited by
                #20

                Dave Kreskowiak wrote:

                If he/she's a wienie, then they have no sense of humor and I would have to leave the company because of this personal condition, which I find hostile to my own creativity and motivation.

                I hear ya. I cannot imagine going through life without having a daily hearty laugh. I usually denote those kind of laughs in these forums with :laugh::laugh::laugh:

                "Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

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                • M martin_hughes

                  Now I don't pretend to know it all, so when I have questions I'm prepared to ask someone who might already have encountered a similar problem and listen to their suggestions. Unlike the muppets I work for. Today's project saw me looking at the feasibility of porting an existing Access database to SQL Server. Easy, thought I, but then I actually saw the "database" in question. To give you just one example of the horrors I'm looking at: The "Machine" table has a "Date Added" column. Now, if you're like me, you'd expect this to be a DateTime column. So I was surprised to see this as a numeric field featuring values such as 1,2,3,4 etc. I was even more surprised to see that this field is related to a "DateAdded" table, whose sole purpose is to give index values to dates. It currently has a seperate entry for each and every day up to 31/12/2015. :wtf:

                  "It was the day before today.... I remember it like it was yesterday." -Moleman

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                  Glen Murtagh
                  wrote on last edited by
                  #21

                  Some Sort Of Myan Calendar?

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                  • M martin_hughes

                    Now I don't pretend to know it all, so when I have questions I'm prepared to ask someone who might already have encountered a similar problem and listen to their suggestions. Unlike the muppets I work for. Today's project saw me looking at the feasibility of porting an existing Access database to SQL Server. Easy, thought I, but then I actually saw the "database" in question. To give you just one example of the horrors I'm looking at: The "Machine" table has a "Date Added" column. Now, if you're like me, you'd expect this to be a DateTime column. So I was surprised to see this as a numeric field featuring values such as 1,2,3,4 etc. I was even more surprised to see that this field is related to a "DateAdded" table, whose sole purpose is to give index values to dates. It currently has a seperate entry for each and every day up to 31/12/2015. :wtf:

                    "It was the day before today.... I remember it like it was yesterday." -Moleman

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                    Bert delaVega
                    wrote on last edited by
                    #22

                    "When normalization goes wrong. Horribly" With that title, I expected to see an old "Far Side" cartoon! The example is pretty funny either way.

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                    • P PIEBALDconsult

                      That's similar to an Excel-based puddle-of-crap I have to support now. Each worksheet has entries for dates up to early this September, there's a formula for determining which row to work on for each date. The problem is that I don't think I can add more rows, so to extend the supported timeframe I'll have to delete the oldest data. Be glad you are at least dealing with a ::cough:: database ::cough::. "Always look on the bright side of life." -- Monty Python

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                      dojohansen
                      wrote on last edited by
                      #23

                      I'm sort of going off on a tangent here, but this reminds me of a most excellent Dilbert stripe a while ago. The pointy-haired boss has called an engineer into his office and says: Boss: My spreadsheet shows your job performance hasn't been very good lately. Engineer: Perhaps your spreadsheet is poorly conceived and does not capture the complexity of the real world. Boss: (silence) Engineer: And let's not forget the near certainty that your formulae are pointing to the wrong cells. Cracked me up! :D

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