The IndexDefs property lists the index definitions for a dataset. While an application can examine IndexDefs to explore the index definitions for a table, it should not change these definitions unless creating a new table with the CreateTable method. To set the active index for a table, use the IndexName or IndexFieldNames property. If the IndexDefs property is updated or manually edited, the StoreDefs property is automatically set to True.
The index definitions in the IndexDefs may not always reflect the current index definitions available for a table unless the table has been opened and the IndexName or IndexFieldNames property has been assigned a value. Before using the index definitions from an existing table for in a call to the AlterTable method, call the Update method to read the index definitions from the actual table.