Re: CREATE TABLE LIKE INCLUDING INDEXES support

From: NikhilS <nikkhils(at)gmail(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "Gregory Stark" <stark(at)enterprisedb(dot)com>, "Neil Conway" <neilc(at)samurai(dot)com>, "Bruce Momjian" <bruce(at)momjian(dot)us>, "Trevor Hardcastle" <chizu(at)spicious(dot)com>, pgsql-patches(at)postgresql(dot)org
Subject: Re: CREATE TABLE LIKE INCLUDING INDEXES support
Date: 2007-05-18 07:26:06
Message-ID: d3c4af540705180026o3921849cicc17c02fcc593ec@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-patches

Hi,

> [ remembering previous discussions more clearly... ] Actually there
> is a concrete problem here: unique constraints are supposed to be
> represented in the information_schema views, and there is no
> spec-compliant way to do that for a constraint on something other than
> a column. We'd have to guess at what the SQL committee would do about
> that, and the odds of guessing exactly right don't seem encouraging.

Considering that a unique index is a unique constraint, then isn't allowing
expressional unique indexes contradictory to the above?

It seems that "CREATE UNIQUE INDEX" currently does not pass isconstraint as
true to DefineIndex, otherwise index_create() would have cribbed with:

"constraints cannot have index expressions" error.

Since this patch is going to consider creating unique/primary indexes
assuming them to be constraints, IMHO we should be uniform about unique
constraints semantics.

That might mean that we only support expressionless, non-predicate indexes
via "INCLUDING CONSTRAINTS"?

Regards,
Nikhils

--
EnterpriseDB http://www.enterprisedb.com

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Magnus Hagander 2007-05-18 07:31:23 Re: What is happening on buildfarm member baiji?
Previous Message Jaime Casanova 2007-05-18 04:54:34 Re: Maintaining cluster order on insert

Browse pgsql-patches by date

  From Date Subject
Next Message Heikki Linnakangas 2007-05-18 08:33:00 Re: Seq scans status update
Previous Message Pavel Stehule 2007-05-18 05:43:23 Re: Updateable cursors patch