On Tuesday, January 5, 2016, Steve Rogerson <steve...@yewtc.demon.co.uk> wrote:
> On 05/01/16 19:47, Tom Lane wrote: > > Steve Rogerson <steve...@yewtc.demon.co.uk <javascript:;>> writes: > >> Is this a bug? I create a "unique" index, directly but it doesn't add a > unique > >> constraint. Add a unique constraint and it adds the index and the > constraint. > > > > That's operating as designed. A unique constraint needs an index, > > but not vice versa. > > > I can see that might be plausible , hence the question but as a "unique > index" > imposes as constraint they seem equivalent. What's the functional > difference > between the two situations? > > I suspect it has to do with partial unique indexes. David J.
