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brkonthru
Starting Member
31 Posts |
 Posted - 2003-02-18 : 19:55:28
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| Hello everyone,I am using SQL2K and was wondering if having a Clustered Primary Key on and ID field in a table makes it unnecessary to add another index for that same ID field.I know when I create a uniqe index on a field, it doesnt make it a Primary Key, but is making a field Primary Key removes the need to add an index to it?Thanks, |
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robvolk
Most Valuable Yak
15732 Posts |
Posted - 2003-02-18 : 20:01:53
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| That's correct. A primary key constraint is by definition unique, and SQL Server will create an index to enforce it. Any other indexes on the key column would be redundant. The only exception would be if you have a multi-column primary key. Indexing the 2nd, 3rd etc. columns might be beneficial if those columns are frequently JOINed to columns in other tables, or are part of the WHERE clause in popular queries. |
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brkonthru
Starting Member
31 Posts |
Posted - 2003-02-19 : 10:04:00
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| Thats the answer im looking for.Thank You. |
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Help needed on Indexes and Primary Keys