Question

Are there any performance difference between decimal(10,0) unsigned type and int(10) unsigned type?

Answer 1

It may depend on the version of MySQL you are using. See here.

Prior to MySQL 5.0.3, the DECIMAL type was stored as a string and would typically be slower.
However, since MySQL 5.0.3 the DECIMAL type is stored in a binary format so with the size of your DECIMAL above, there may not be much difference in performance.

The main performance issue would have been the amount of space taken up by the different types (with DECIMAL being slower). With MySQL 5.0.3+ this appears to be less of an issue, however if you will be performing numeric calculations on the values as part of the query, there may be some performance difference. This may be worth testing as there is no indication in the documentation that i can see.

Edit:
With regards to the int(10) unsigned, i took this at face value as just being a 4 byte int. However this has a maximum value of 4294967295 which strictly doesn’t provide the same range of numbers as a DECIMAL(10,0) unsigned .

As @Unreason pointed out, you would need to use a bigint to cover the full range of 10 digit numbers, pushing the size up to 8 bytes.

A common mistake is that when specifying numeric columns types in MySQL, people often think the number in the brackets has an impact on the size of the number they can store. It doesn’t. The number range is purely based on the column type and whether it is signed or unsigned. The number in the brackets is for display purposes in results and has no impact on the values stored in the column. It will also have no impact of the display of the results unless you specify the ZEROFILL option on the column as well.