Roy is talking about database sins.  I worked on porting one database that had to be the worst I’ve ever seen in my entire career.

First off, it was an Access database.  It starts off well doesn’t it?  J  Well, it was an Access database split into two parts (the front file and the back file), each a couple hundred MB each.  And they used the ldb locking file to manage roles, passwords, etc.  Great huh?  It gets better.

There were 100 tables or so.  Some were in the front file, some were in the back file, some were in both and were not linked tables!

There was not one relation in the entire database!

One table held 5 different types of objects.  True they were related to each other, but not the same.  The VBA code was littered with if(type = A) then do x elseif (type=B) then do y etc.

All forms would select * from tableName, even if the form only needed one value.  Oh, and it did this with the table that held 5 different types of objects (which were the centerpiece of the domain model, thus there were lots of records in the table), so some forms took 2 minutes to open while it selected the entire table, and then filtered the results to typeA only and then displayed 5 of the fields!

And beside the primary key identifier on some of the tables (some tables had none), all fields were nullable!  There were probably 25,000 IsNull checks in the VBA code.

There was more, but the rest was peanuts compared to this!