No, a primary key is by definition UNIQUE (and NOT NULL) and the access path already exists.
The question is, is the implicitly created index needed for primary key and/or unique constraints
different from the index created using CREATE INDEX.
I didn't think so, but the fact that you're being advised to create one would refute that.
Even so, I would think that the "access path" itself _HAS_ to be the same; no matter if it was in an
implicit index or an explicit one. So the only difference would be statistics kept by an implicit
index vs. an explicit index.
CINTAS Corporation - IT 92B
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-
bounces@xxxxxxxxxxxx] On Behalf Of Jeff Crosby
Sent: Friday, April 11, 2008 9:33 AM
To: Midrange Systems Technical Discussion
Subject: Re: Index advisor advising index on primary key
Oooh. So if I did an ALTER TABLE and added a UNIQUE constraint on this
file, that might do it?
Mark S. Waterbury wrote:
You said "primary key" but did not indicate whether this column has a
(I know that when you add a unique constraint to a table or file it
creates an index (access path) under the covers.)
> Jeff Crosby wrote:
On our item master file, it is advising that I create an index on field
ITNBR. This file is an SQL table created via DDL (not DDS) and ITNBR
the primary key. Does this advice make sense? Why would it advise an
index on the primary key?
Opinions expressed are my own and not necessarily those of my company.
Unless I say so.
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
This e-mail transmission contains information that is intended to be confidential and privileged. If you receive this e-mail and you are not a named addressee you are hereby notified that you are not authorized to read, print, retain, copy or disseminate this communication without the consent of the sender and that doing so is prohibited and may be unlawful. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please delete and otherwise erase it and any attachments from your computer system. Your assistance in correcting this error is appreciated.