From: "Niall Litchfield" Newsgroups: comp.databases.oracle.server References: <1031553251.430831@news.thyssen.com> Subject: Re: Primary and Foreign Key constraints Date: Mon, 9 Sep 2002 09:11:45 +0100 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Lines: 38 Message-ID: <3d7c57c0$0$1289$cc9e4d1f@news.dial.pipex.com> NNTP-Posting-Host: usercp95.uk.uudial.com X-Trace: 1031559104 news.dial.pipex.com 1289 62.188.156.124 X-Complaints-To: abuse@uk.uu.net "Lars Steinmetz" wrote in message news:1031553251.430831@news.thyssen.com... > Hello NG, > > I have an Oracle Database witch work's with an old client software > programmed i C++. The client software installed all tables, indexes, > sequences ect. by itself. Looking into the Oracle-DB, I recognized that no > primay and no foreign key constraints are implemented. That means that all > referneces are only known by the client program. Not very stylish... > Will adding primary key and foreign key constraints to the databases > increase the performance? > > Thanx for any response. It depends! If the keys are already indexed then I'd suggest the performance benefits you'd get would be slight. It seems quite likely to me that you will have unindexed FK's though. The other thing to consider is wether yu would be invalidating the vendor's support by doing this sort of thing. My guess would be that you are. What happens if the key you identify as a foreign key turns out not in fact to be a foreign key at all. -- Niall Litchfield Oracle DBA Audit Commission UK ***************************************** Please include version and platform and SQL where applicable It makes life easier and increases the likelihood of a good answer ******************************************