Have someone experienced problemns with multiple field indexes, like: field1 + dtos(field2) + str(field3)... Problemns like: slow indexes, corrupted indexes, etc...

I need that for primary key.

Cause I have developed a database that have until 6 fields concatenated on one single tag, and the tables will have a lot of records (1 million+).

Any experience will be apreciated.
Thanks.