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Schema: Wrong data types
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
Most RDBMS don't have too many data types, with PostgreSQL being an exception via its powerful EXTENSIONS system. Even so, using the correct data type has at least these benefits:
- Data integrity: One case of incorrect data less to worry about.
- Documentation: Even if your client application might make sure you'll never get e.g. non-numeric values in a
VARCHARcolumn, it's still better to formally communicate this fact through types. - Performance: Without proper statistics, the optimiser might make the wrong estimates simply because of wrong data types being used.
For example
CREATE TABLE transaction ( -- [...] amount TEXT NOT NULL, -- Amount is probably a DECIMAL or NUMERIC value, so why not use that? value_date TEXT NOT NULL -- But it's a date, so why not use DATE or TIMESTAMP? );
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