We want to create an index that contains ONLY SOME VALUES of a field. What kind of index do we have to use?

For example. Assume that we have a table with1billion rows. Let name of a field is RECORD_STATUS. Number of rows for which record_status=0 is only. We want to create an index that contains only record_status=0 records. So even table has1billion records, this index will contain only rows' address.