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Home > Archive > microsoft.public.sqlserver.server > December 2002 > Foreign Key indexes
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Foreign Key indexes
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| Jake Dutra 2002-12-06, 10:23 am |
| Simple question: Does SQL Server use the foreign key
constraint like an index? Or do I need to create a
separate index for it to be used in SELECT statements.
In other words, SELECT * FROM TABLEX WHERE COL1=2 ---if
COL1 has a foreign key constraint, do I still need to add
an index if I want an index used in the select statment?
Thanks
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| Kalen Delaney 2002-12-06, 10:23 am |
| An index is a separate physical structure, and defining a foreign key does
not create this structure. Only Primary Key and unique constraints will
build indexes. If you want an index on a column defined as a FK, you must
create one.
HTH
--
Kalen Delaney
SQL Server MVP
"Jake Dutra" <webster0001@hotmail.com> wrote in message
news:0b1f01c29d3b$abc23ce0$d5f
82ecf@TK2MSFTNGXA12...
> Simple question: Does SQL Server use the foreign key
> constraint like an index? Or do I need to create a
> separate index for it to be used in SELECT statements.
> In other words, SELECT * FROM TABLEX WHERE COL1=2 ---if
> COL1 has a foreign key constraint, do I still need to add
> an index if I want an index used in the select statment?
> Thanks
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