I have the following table:
tickername | tickerbbname | tickertype
------------+---------------+------------
USDZAR | USDZAR Curncy | C
EURCZK | EURCZK Curncy | C
EURPLN | EURPLN Curncy | C
USDBRL | USDBRL Curncy | C
USDTRY | USDTRY Curncy | C
EURHUF | EURHUF Curncy | C
USDRUB | USDRUB Curncy | C
I don't want there to ever be more than one column for any given tickername/tickerbbname pair. I've already created the table and have lots of data in it (which I have already ensured meets the unique criteria). As it gets larger, though, room for error creeps in.
Is there any way to add a UNIQUE constraint at this point?