I am working on building a small Mysql database for our team. For two tables in my db, I used the same index name.
Would there be any performance hit?
I did
No. The index name is completely inconsequential to performance.
Index names are per table, there shouldn't be any concern.
Index names are specific to each table. You cannot have two indexes of the same name in one table, but you can have many indexes of the same name, one for every table. Index names are irrelevant for day-to-day performance. They're simply there to provide a nice user-friendly way to refer to the index without having to list all the fields in the index. e.g. it's easier to say alter table XXX drop key friendlyname
than alter table XXX drop key (field1, field2, field3, field4, field5, etc...)