On Tue, 3 Aug 2010 14:55:24 +0200, Staffan Tylén wrote: >I may be completely wrong but aren't search engines using similar bit maps >to indicate where things can be found? So to get the number of hits one >would need to count all those '1' bits.
Along the same lines: If DB2 uses bit maps for active pages then I can see some real value for the DB2 optimizer using POPCNT to determine how many pages it will need to scan and thus the cost of the query and which index to use.
