Is it possible to add a column to an existing clustered index in sql server?
You can change the definition of a clustered index (i.e. add a new column to the keys) as an online operation. I don't have an instance to check, but the syntax is as follows:
create clustered index [indexname] on [table]( ) with (drop_existing =on, online = on);
The operation is completely online (the table is open for reading, inserting, updating and deleting). You need an Enterprise Edition instance (since only EE supports online index creation operations), and the table cannot have LOB columns (at least not until SQL Server 2012 ).
The operation is a complete rebuild of a table, resource heavy and generating a significant log.
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