Do index names have to be unique across entire database in Mysql?

Question

For example, if I have two tables Teacher and Student that would have a column named IDNumber, do I have to name the indexes separately like this:

IDNum_teach IDNum_stu  

Or could I just create an index on each table for IDNumber and name them both IDNum?

Answer 1

Yes you can use same index name for both the tables.

CREATE [UNIQUE|FULLTEXT|SPATIAL] INDEX IDnum [index_type] ON tbl_name (index_col_name,...) [index_type]

Answer 2

Each table in an SQL database is essentially independent. So, yes, you can use the same column name IDNumber in each table.