Re: UNIQUE constraint and indexing

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

Yes. It is better to think of "Unique" as creating an index with the added
benefit of a "unique" constraint.

Keary Suska
Esoteritech, Inc.
"Leveraging Open Source for a better Internet"

> From: Arcady Genkin <a.genkin@utoronto.ca>
> Date: 01 Oct 2001 10:45:18 -0400
> To: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] UNIQUE constraint and indexing
> 
> 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
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
> 
> http://archives.postgresql.org
>