I
was assigned a tricky problem to work on. Some of the data was missing in our
production environment. Everything seemed to work fine in development and test.
Trouble is, I did not have access to the production environment. I got someone
to run some queries on my behalf.
The
source data was correct. The target tables had records inserted. But they were
missing key fields. This was quite the mystery. I had to back up and look at
the big picture. Normally this is not needed. But in this case, it was crucial.
We
have some main data loaded into some staging tables. Then some processes run
after the initial load that collect all the data and stuff it into a couple
main tables. Then those main table are copied to the reporting machine. It is
here that my jobs run to mine the main tables to update the reporting tables.
Turns
out the copy to the reporting machine is delayed every so often. Wouldn’t you
know it? My jobs are not actually scheduled to wait until the copying of source
data is completed. Usually it happens way before my jobs run. But not always.
The
fix is to add in the dependency, and fix all those records that got loaded with
blanks. The hard part of this problem was figuring out the source of the
problem. Wasn’t really a coding issue. More a timing issue.
