Hi all, I have a question about the best way to have a constrain on a table.
think to a DB with 2 fields in the table ColA and ColB and you don't
want to have multiple records with the same ColA,ColB couple
so we can
CONSTRAINT ColA_ColB UNIQUE (ColA,ColB) in the create table
or
CREATE UNIQUE INDEX uq_ColA_ColB ON table(ColA, ColB)
which one do you think is better in terms of performance? keep in mind
the table have millions of records and SELECT is the most frequent operation
--
Selea s.r.l.
Michele Pradella R&D
SELEA s.r.l.
Via Aldo Moro 69
Italy - 46019 Cicognara (MN)
Tel +39 0375 889091
Fax +39 0375 889080
*michele.pradella at selea.com* <mailto:michele.pradella at selea.com>
*http://www.selea.com*
