Sets or returns a value that indicates whether records that have Null values in their index fields have index entries (Microsoft Jet workspaces only).
Settings and Return Values
The setting or return value is a Boolean that is True if the fields with Null values don't have an index entry. This property is read/write for a new Index object not yet appended to a collection and read-only for an existing Index object in an Indexes collection.
Remarks
To speed up the process of searching for records, you can define an index for a field. If you allow Null entries in an indexed field and expect many of the entries to be Null, you can set the IgnoreNulls property for the Index object to True to reduce the amount of storage space that the index uses.
The IgnoreNulls property setting and the Required property setting together determine whether a record with a Null index value has an index entry.
If IgnoreNulls is | And Required is | Then |
True | False | A Null value is allowed in the index field; no index entry added. |
False | False | A Null value is allowed in the index field; index entry added. |
True or False | True | A Null value isn't allowed in the index field; no index entry added. |