Re: UNIQUE constraint and indexing

Arcady Genkin <a.genkin@utoronto.ca>

From: Arcady Genkin <a.genkin@utoronto.ca>
To: pgsql-general@postgresql.org
Date: 2001-10-01T14:45:18Z
Lists: pgsql-general
Stephan Szabo <sszabo@megazone23.bigpanda.com> writes:

> On 27 Sep 2001, Arcady Genkin wrote:
> 
> > Is the index, created implicitely by "UNIQUE" constraint, the same
> > kind as created explicitely with "CREATE INDEX"?  In other words,
> > is the following piece of SQL redundant?
> > 
> > create table foo (
> >        bar serial primary key,
> >        baz text not null unique );
> > create index foo_baz_idx on foo(baz);
> 
> Apart from the index for unique being a unique index, I believe so.

So, the unique index will still be used when processing SELECT
queries, right?  In other words, is the index foo_baz_idx redundant?

THanks,
-- 
Arcady Genkin