All,
Cache is pretty fast, but that is because it keeps a lot of data in memory all of the time in 'global counters.' But try to access the data? Good luck.
If you use ODBC, sometimes it will take several minutes to tell you there are no results. I have used this in both a banking and medical/mental health environment. Third party access to the data is pretty slow.
Often times data you need is not 'mapped,' so as a third party you cannot access it via ODBC. Plus if there is a 'mistake' in the table/field mappings the ODBC will return you interesting errors. The 'structures' are always in a state of transition, so these mapping problems rear their ugly heads uncomfortably often.
Just my .02
Doug