Database development mistakes made by application developers [closed]

Answer 1

1. Not using version control on the database schema
2. Working directly against a live database
3. Not reading up and understanding more advanced database concepts (indexes, clustered indexes, constraints, materialized views, etc)
4. Failing to test for scalability ... test data of only 3 or 4 rows will never give you the real picture of real live performance

Answer 2

Here is a link to video called ‘Classic Database Development Mistakes and five ways to overcome them’ by Scott Walz

Answer 3

Not doing the correct level of normalization. You want to make sure that data is not duplicated, and that you are splitting data into different as needed. You also need to make sure you are not following normalization too far as that will hurt performance.

Answer 4

The most common mistake I've seen in twenty years: not planning ahead. Many developers will create a database, and tables, and then continually modify and expand the tables as they build out the applications. The end result is often a mess and inefficient and difficult to clean up or simplify later on.

Answer 5

Using Excel for storing (huge amounts of) data.

I have seen companies holding thousands of rows and using multiple worksheets (due to the row limit of 65535 on previous versions of Excel).

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Excel is well suited for reports, data presentation and other tasks, but should not be treated as a database.

Answer 6

• Dismissing an ORM like Hibernate out of hand, for reasons like "it's too magical" or "not on my database".
• Relying too heavily on an ORM like Hibernate and trying to shoehorn it in where it isn't appropriate.