Why is Index column by default Decimal Number?

[richard-powerbi]

Usually an added Index column is a Whole Number as far as my experience goes.

Why is it by default a Decimal Number in Power Query?

As a result I'm always adding a step to make it a Whole Number. 

• Is it possible to add an Index column with my desired Data Type directly?

In general I'm wondering what's best practice for performance out of these options:

• Adding extra step in Power Query for changing Data Type to Whole Number
• Change Data Type under Data > Modeling to Whole Number
• Leave it at Decimal Number

[Anonymous]

Because you may want to increment by .1 or .01. 

Most CPUs handle floating point (decimal) numbers as efficiently as integers (whole numbers). I would not think that performance improves by changing the type to whole number.

Regards,

Mike