Use IndexName to specify an alternative index for a table. If IndexName is empty, a table's sort order is based on its default index, or, for dBASE tables, on its physical record order. 

If IndexName contains a valid index name, then that index determines the sort order of records. For dBASE tables, an index name supplied to the IndexName property must either reside in the table's master index file, or in another index file already specified in the IndexFiles property.

IndexFieldNames 

IndexFiles 

DefaultIndex 

Specifying a dBASE Index File 

Specifying the Data to Display using TSQLDataSet 

Using TTable