Paul Hartley wrote:
> I have a composite primary key for a table, let's call it
> (col1, col2). When this table is created, obviously an
> implicit index is created for this key. I would like the
> sort order of this index to be different for the two columns
> -- if I were to create the index myself, I would pass on
> (col1, col2 DESC). The ALTER INDEX documentation suggests
> that it's not possible to change the sort order of a column,
> so I can envision two ways to get around this: 1) create a
> second UNIQUE index of (col1, col2 DESC), or 2) not define a
> primary key and just specify a UNIQUE index separately.
> Primary keys are basically restricted to being unique and
> non-null, but I'm unclear if PostgreSQL treats primary keys
> differently from unique, non-null constraints.
I think you can safely go for 2).
Although I admit it is not pretty.
Yours,
Laurenz Albe