Fig. 8.4.2 shows that as data are captured, especially in the online environment, the data
have its first occurrence of the system of record. Location 1 shows that the system of
record for current valued data is found in the online environment. You can think of
calling the bank and asking for your account balance that exists right now, and the bank
looks into its online transaction processing environment to find your account balance
right now.

Then one day, you have an issue with a bank transaction that occurred 2 years ago. Your
lawyer requires you to go back and prove that you made a payment 2 years ago. You
can’t go to your online transaction processing environment. Instead, you go to your
record in the data warehouse. As data age, the system of record moves for older data to
the data warehouse. That is location 2 in the diagram.

Time passes and you get audited by the IRS. This time, you have to go back 10 years time
to prove what financial activity you have had a decade ago. Now, you go to the archival
store in big data. That is location 3 in the diagram.

So, as time passes, the system of record for data changes in data architecture.

Different Types of Questions

Another way to look at the data found in data architecture is in terms of what types of
questions are answered in different parts of the architecture.

Fig. 8.4.3 shows that different types of questions are answered in different parts of the
architecture.

Chapter 8.4: Data Architecture: A High-Level Perspective