Please note : This help page is not for the latest version of Enterprise Architect. The latest help can be found here.

SQL Server Non Clustered Keys

When you create a Primary Key in SQL Server, it is created with a 'clustered index' by default. Therefore when you model a Primary Key for SQL Server in an Enterprise Architect data model, the corresponding DDL creates a clustered index for that Primary Key by default.

Clustered indexes provide improved performance for accessing the column(s) involved, but only one clustered index is allowed per Table.

In some situations, you might be more interested in the performance of columns other than the Primary Key, and therefore must change the default assignment of the clustered index. Enterprise Architect helps you to model this.

Access     On diagram | Right-click on Table element | Features & Properties | Operations > Constraints

Define Primary Key as non-clustered for a SQL Server Table



See also


Highlight the existing Primary Key Operation.

The Primary Key properties display in the Property panel.




For the Non Clustered property, in the Value field click on the drop-down arrow and change the value to True.



Subsequently, you can model an index for the Table and define that as clustered instead.

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