John, If absolute raw speed is what you are looking for I would break each value into whole numbers - the integer and the decimal and store them separately as longints. Index the integer with a b-tree and the decimal with a cluster. You sacrifice space (maybe - haven't really done the math on 2 longs vs 1 real) but space is cheap and you want speed.
On Thu, Apr 9, 2020 at 8:53 PM John J Foster via 4D_Tech < [email protected]> wrote: > Hi All, > > I have a GEO database of almost 5 million cities. They include various > data and latitude and longitude. > > I need to use the Longitude file in searches. To speed it up I need to > index. Many of the values are similar like 141.235 or 141 3.23 and so on. > So for those who might know would a Cluster index be better suited or a > B-Tree? > > Thanks, > John… > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > Archive: http://lists.4d.com/archives.html > Options: https://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:[email protected] > ********************************************************************** -- Kirk Brooks San Francisco, CA ====================== ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
