Question

I need to check if a particular record in a (potentially) large database (millions of records) exists.

I can choose to uniquely identify the record with:

• 2 integer numbers (example: 231321 and 312309)
• 1 float number (a combination of the two integer numbers. example: 231321.312309)
• 1 string (a combination of the two integer numbers. example: ‘231321@312309’)

Is one of these three options better than the others?

Thanks!

Answer 1

Use 2 integers.

Rationale:

• Depending on actual integer range, you might not be able to store 2 integers
  in a single float without loss of precision.
• String is just a waste of space.
• For both float and string, you won’t be able to index (and therefore search efficiently) on the second integer, if you ever need to.
• Also, there is a philosophical argument about atomicity and that violating it actually violates the 1st normal form.