[postgis-users] selectivity
Ben
midfield at gmail.com
Mon Nov 1 16:18:30 PDT 2010
hello --
i am not a postgis user, but i am interested in range datatypes and gist indexing. there are some extensions for postgresql which expose such types (temporal, cube, etc.) but as far as i can tell all of them use the default geometric operator selectivity functions, which are all stubs in mainline postgresql and return hard-coded constants -- not ideal.
i've been investigating postgis and it appears that you have real selectivity functions for your operators.
1 - is this true? do they work well? which operators work? (&&, @>, etc)?
2 - is there any documentation describing how they work (besides the source code)? i'm interested in the kind of statistics you use.
3 - would it be possible for someone to backport the selectivity functions to, say, temporal postgres or cube? would you recommend it?
best regards, ben
More information about the postgis-users
mailing list