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Chapter 5.1: The Siloed Application Environment
           Current valued data are data that are accurate as of the moment of access. In order to
           achieve this high degree of accuracy, the application must support online transaction
           processing.


           As a simple example of current value data, consider the account balance for a husband
           and a wife. At 8:00 a.m., their account balance has $5000. At 9:15 a.m., the wife does an
           ATM withdrawal of $500. At 9:15 a.m. and 5 seconds, the account balance is corrected

           to $4500.

           The husband checks the account balance at 10:00 a.m. and sees that the account balance

           is $4500. The husband withdraws $175 as of 10:01 a.m. At 10:01 a.m. and 5 seconds, the
           account now has $4325.


           At 4:15 p.m., the wife deposits a check into the account for $2000. As of 4:15 p.m. and 5
           seconds, the account balance is now $6325.


           At any point in the day, the husband, the wife, and the bank can check the account
           balance and see what the balance in the account is. The account balance is accurate as of
           the moment of access to the data.


           Current value data are data that are accurate as of the moment of access. Applications
           that interact directly with the customer are typically populated with current value data.


           The converse of current value data is data that are not accurate as of the moment of
           access. As a simple example of noncurrent value data, consider the stock market where
           values are captured at the end of the trading day. Suppose there is an application that
           captures data as of the end of a trading day.


           At 9:00 a.m., you look at your favorite stock. You found that its closing value the day
           before was $76.10. However, the market has been open for several hours now. The stock
           may well be trading higher or lower than $76.10. But your stock value won’t be updated
           until the end of the trading day.



           Minimal Historical Data



           Another characteristic of the data found in siloed applications is that there is relatively
           little historical data found in the application. If there is any amount of historical
           information found in the application, it is summarized.


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