Re: Request: set opclass for generated unique and primary - Mailing list pgsql-hackers

From Stephan Szabo
Subject Re: Request: set opclass for generated unique and primary
Date
Msg-id 20060222145513.D79453@megazone.bigpanda.com
Whole thread Raw
In response to Re: Request: set opclass for generated unique and primary key indexes  ("Pavel Stehule" <pavel.stehule@hotmail.com>)
Responses Re: Request: set opclass for generated unique and primary key indexes
List pgsql-hackers
On Wed, 22 Feb 2006, Pavel Stehule wrote:

> > > >I seem to recall someone proposing extending the syntax of the UNIQUE
> > > >constraints themselves, but there really isn't enough use-case to
> > > >justify it AFAICS.  Especially not when you can always use CREATE
> >UNIQUE
> > > >INDEX.
> > >
> > > I can always use second unique index. But it's redundant. This problem
> >is
> > > related to using nonC locale.
> >
> >Why do you need both the unique index with varchar_pattern_ops and one
> >with the default ops?
>
> Because LIKE op don't use index on default ops with non C locale. I found it
> on tables of czech communities. Primary key is NUTS - 4..6 numbers.  I have
> to search values with some prefix -> op Like and on primary key can't to use
> std. index.

Right, but does the pattern_ops one have to be unique?
And if it does, do you need the normal unique constraint as well?


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