Re: Foreign key & User defined Index Difference

Article View: borland.public.interbase.sql

Article #470

Back to borland.public.interbase.sql Previous Next

#470

From: Bill Todd
Date: Fri, 30 Nov 2007 20:50

12 lines
1532 bytes

Quinn Wildman (CodeGear Developer Support) wrote:

> Depending on your version of InterBase, foreign keys may have a
> higher selectivity. So, the optimizer may choose to do things
> differently for foreign keys vs user defined indexes.

Could you expand on that? How can two identical indexes have different
selectivity just because one was created automatically as part of a
foreign key and one was created with CREATE INDEX?

-- 
Bill Todd (TeamB)

Technical Details

Message-ID: <475085be$1@newsgroups.borland.com>

Path:

arc1-ca.pugleaf.net!g2news1.google.com!news4.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!club-internet.fr!feedme-small.clubint.net!news.germany.com!newsfeed01.sul.t-online.de!t-online.de!newsgroups.borland.com!not-for-mail

References: <474fc025$1@newsgroups.borland.com> <47507fad@newsgroups.borland.com>

Show Full Headers

Complete Article Headers

X-Google-Thread: 114a0e,e8cd02e29a9aa333
X-Google-Attributes: gid114a0e,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
From: "Bill Todd" <no@no.com>
Subject: Re: Foreign key & User defined Index Difference
Newsgroups: borland.public.interbase.sql
References: <474fc025$1@newsgroups.borland.com> <47507fad@newsgroups.borland.com>
Organization: The Database Group, Inc.
User-Agent: XanaNews/1.18.1.6
X-Face: ":yn4zt^A_dn>6~{YJmu^B\'4w)e:apPM\VC=Dvf&*tASxX9|BYczkFd$xr.$vNSZ[3Uobr p]c4\+\l){!WQI.$]veP({HLd;CDYH?iN
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
NNTP-Posting-Host: 65.118.176.23
Message-ID: <475085be$1@newsgroups.borland.com>
Date: 30 Nov 2007 13:50:54 -0700
X-Trace: newsgroups.borland.com 1196459454 65.118.176.23 (30 Nov 2007 13:50:54 -0700)
Lines: 12
X-Authenticated-User: btodd
Path: arc1-ca.pugleaf.net!g2news1.google.com!news4.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!club-internet.fr!feedme-small.clubint.net!news.germany.com!newsfeed01.sul.t-online.de!t-online.de!newsgroups.borland.com!not-for-mail

Reply to Parent Message