Specifies whether an index should be created on a field.
Settings and Return Values
Sets or returns a Boolean value that indicates whether an index should be created.
Remarks
An index can improve the performance of operations that find or sort values in a Recordset. The index is internal to ADOùyou cannot explicitly access or use it in your application.
To create an index on a field, set the Optimize property to True. To delete the index, set this property to False.
Optimize is a dynamic property appended to the Field object Properties collection when the CursorLocation property is set to adUseClient.
Usage
Dim rs As New Recordset
Dim fld As Field
rs.CursorLocation = adUseClient 'Enable index creation
rs.Fields.Append "Field1", adChar, 35, adFldIsNullable
rs.Open
Set fld = rs.Fields(0)
fld.Properties("Optimize") = True 'Create an index
fld.Properties("Optimize") = False 'Delete an index