Databases are pessimization playland.
Favorites include:
- Split a table into multiples (by date range, alphabetic range, etc.) because it's "too big".
- Create an archive table for retired records, but continue to UNION it with the production table.
- Duplicate entire databases by (division/customer/product/etc.)
- Resist adding columns to an index because it makes it too big.
- Create lots of summary tables because recalculating from raw data is too slow.
- Create columns with subfields to save space.
- Denormalize into fields-as-an-array.
That's off the top of my head.
