Collective Wisdom from the Experts 129
As it turns out, the views that had been deleted were the source for the missing
customer data.
Since the source views were deleted to complete the upgrade, the synchroniza-
tion process between the systems was broken. We had to spend hours trouble-
shooting the system before we came to the conclusion that the source views
were missing. Then we had to recreate the deleted views, by hand, in order to
get the two systems talking again.
Most IT departments have diagrams showing how the various components of
their hardware systems are connected. But we’ve found it is equally helpful to
have a visual representation of how data flows throughout our organization.
Show the crucial junctures where data from one application flows into other
programs.
We learned that in situations like this, it helps to have good documentation
illustrating where your systems are reliant on one another. When we initially
met with the vendor engaged to manage our upgrades, we could have shared
our business flow diagram.
The initial upgrade problems could have been solved in another way, rather
than deleting crucial views that fed other systems. We could have saved our-
selves downtime and administrator stress, and come out of the upgrade process
confident that we didn’t have to live in fear that other, hidden problems had
been introduced to the system.