On 1/19/07, Garth Keesler <garthk@gdcjk.com> wrote:
> I have a primary key made up of two varchar(128) columns, typically less
> than 16 chars each. Concatenating the two columns would still be unique.
> Would it make sense to concat the two columns, using a unique separator
> like '~' and index on that single column or would that be more trouble
> than the potential performance gains?
yes. use a multiple key index. that is what they are for. or let the
db do it for you:
create table foo (a text, b text, primary key(a,b));
merlin
