如果需要对DataTable进行大批量Select查询，首先为表创建DataView

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconviewingdataindatatable.asp

Tip   If you will be performing a number of calls to the Select method of a DataTable, you can increase performance by first creating a DataView for the DataTable. Creating the DataView will index the rows of the table. The Select method will then use that index, significantly reducing the time to generate the query result. For information about creating a DataView for a DataTable, see Creating and Using DataViews.