Posted by Dan Guzman on 09/23/07 12:25

> Check with sysindexes to see if SQL Server does this too.

As Erland mentioned, SQL Server does not automatically index foreign key
columns. That task is left to the discretion of the DBA, who might choose
not to index the foreign column(s) due to low cardinality and static data.

--
Hope this helps.

Dan Guzman
SQL Server MVP

"Tom van Stiphout" <no.spam.tom7744@cox.net> wrote in message
news:8qqbf3190hk4cis52502s9th2ebsjjfpd5@4ax.com...
> On Fri, 21 Sep 2007 19:51:14 -0000, "bobdurie@gmail.com"
> <bobdurie@gmail.com> wrote:
>
> Microsoft Access does this, when you create a relationship between two
> tables.
> Check with sysindexes to see if SQL Server does this too.
>
> -Tom.
>
>
>>If i create a simple table with a foreign key constraint, does it
>>create an implicit index on that given ID? I've been told this is
>>done in some databases, but i need to know for sure if SQL Server does
>>it. Has anyone heard of this before, on any other databses perhaps?
>>
>>Heres an example of how the foreign key constraint is being added:
>>
>>ALTER TABLE [dbo].[administrators] WITH CHECK ADD CONSTRAINT
>>[FPSLUFSUOXZGAJOJ] FOREIGN KEY([AdministratorRoleID])
>>REFERENCES [dbo].[administratorroles] ([AdministratorRoleID])
>>
>>My initial testing seems to indicate adding an index on the foreign
>>key column helps, but i need to know for sure. Any insight would be
>>greatly appreciated!
>>
>>Bob

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