A major pharmaceutical firm had just completed a large software development project using Oracle.
After significant testing in the test and UAT environment, including volume testing, the project rolls out and goes into widespread use. Shortly after production, the users begin to complain about slow performance.
The development team is puzzled, the system works fine in UAT, and the production environment has the same amount of data, in fact, it is the SAME DATA, as the data that was present in UAT. The data was simply copied over into production for the launch.
How can the system be slower in production? After three days of working through all the possible causes that they could think of, the client calls Buda on Friday night to help resolve the problem.
By employing our systematic approach to finding and resolving bottlenecks, we quickly identify the problem, stale statistics.
While the DBA thought (insisted) that statistics were being refreshed each night, in actual fact, only the structure was being validated and the statistics were stale.
A quick revision and execution of the database maintenance scripts and the system returned to expected performance! What seemed to be a disaster for the implementation team turned out to be a simple change and all was well by Monday Morning!