VERIFIED SOLUTION i

Understanding how MapInfo Pro treats very large numbers compared to Oracle

Product affected: MapInfo Pro™

 
User exporting data from Oracle to MapInfo Pro 17 64-bit noticed that when the numbers being exported were 20 digits or more, the complete number was not being exported in to MapInfo Pro and was being truncated.

This is because Oracle can support numbers that are 38 digits long while MapInfo Pro cannot.
MapInfo Pro's "LargeInt" format (64-bit integer) can support numbers 19 digits long.
The "Float" format can handle numbers that are larger but they actually can only handle 16 significant digits.
If these are simple ID fields and math operations with them are not required, the suggestion from Engineering would be to treat them instead as "strings".
UPDATED:  May 29, 2019