Re: disabling foreign keys
From: Greg Rahn <greg_at_structureddata.org>
Date: Tue, 15 Feb 2011 16:20:16 -0800
Message-ID: <AANLkTi=KJs60dqQX0-1=sbFp-OSKFqumjQFyvYgvdmCe_at_mail.gmail.com>
If they are disabled, no, the optimizer can not use them. Other tools may use the metadata and even if they are in a disabled state (ERD tools etc) which may be desirable.
Date: Tue, 15 Feb 2011 16:20:16 -0800
Message-ID: <AANLkTi=KJs60dqQX0-1=sbFp-OSKFqumjQFyvYgvdmCe_at_mail.gmail.com>
If they are disabled, no, the optimizer can not use them. Other tools may use the metadata and even if they are in a disabled state (ERD tools etc) which may be desirable.
On Tue, Feb 15, 2011 at 3:16 PM, Clay Colburn <clay.colburn_at_gmail.com> wrote:
> I have a database that is a data warehouse, so we bulk load data daily and
> tune the database for heavy read operations. I noticed that all of the
> foreign keys in the database are disabled. This obviously aids in the speed
> of the loading process and the relationships can be verified during the ETL
> process.
> My question is, are there any benefits to having these disabled constraints
> laying around beyond just having a sort of meta-data description of the
> foreign key relationships? Does the optimizer use these at all?
> Thanks!
-- Regards, Greg Rahn http://structureddata.org -- http://www.freelists.org/webpage/oracle-lReceived on Tue Feb 15 2011 - 18:20:16 CST