How to: Create XML Indexes (Visual Database Tools)
Use an XML index to create indexes for columns of the data type xml, which cannot be indexed using the Index/Keys dialog box. Each xml column can have more than one XML index, but the first one created (primary) will be the basis of the others. If you delete the primary XML index, the others will also be deleted.
To create an XML index
In Object Explorer, right-click the table for which you want to create an XML index and click Design.
The table opens in Table Designer.
Select the xml column for the index.
From the Table Designer menu, click XML Index.
In the XML Indexes dialog box, click Add.
Select the new index in the Selected XML Index list and set properties for the index in the grid to the right.