I wish that I didn't have to say this, but that is over my head at this point. I see this HUGE, steep mountain ahead of me and a little sign in front of it saying, "Learning Curve, start here." :-) Dennis Gearon Signature Warning ---------------- EARTH has a Right To Life I agree with Bolivian President Evo Morales # The right to life: "The right for no ecosystem to be eliminated by the irresponsible acts of human beings." # The right of biosystems to regenerate themselves: "Development cannot be infinite. There's a limit on everything." # The right to a clean life: "The right for Mother Earth to live without contamination, pollution. Fish and animals and trees have rights." # The right to harmony and balance between everyone and everything: "We are all interdependent." See the movie - 'Inconvenient Truth' See the movie - 'Syriana' --- On Sun, 7/12/09, Brent Wood <b.wood@xxxxxxxxxx> wrote: > From: Brent Wood <b.wood@xxxxxxxxxx> > Subject: Re: indexes on float8 vs integer > To: gearond@xxxxxxxxxxxxx > Date: Sunday, July 12, 2009, 9:10 PM > You might look at UMN mapserver or > Geoserver to provide PostGIS data via WMS/WFS and OpenLayers > to plot these layers on top of Google Maps. These tools > facilitate this sort of online map production pretty easily, > although hosting can be an issue as teh requirements become > more specific. > > Cheers, > > Brent > > > Brent Wood > DBA/GIS consultant > NIWA, Wellington > New Zealand > >>> Dennis Gearon <gearond@xxxxxxxxxxxxx> > 07/13/09 1:05 PM >>> > > Well, Brent, > I'm just getting started on this > design. I'm doing it at a hosting site, initially, so I have > to find out if they have or will load this module. > At first, I was just going to > interpolate the distance as a bounding box based on the > distance between latitude lines and longitude lines at that > latitude. Then serve the data based on the integers for > lat/long between two values. All the geographic calculations > would have taken place in the server app, then postgres > would only be working with integers. > So, what is the base type for the > point column? > I had planned on using google maps > as the geographic server, I was going to query them using > their API and a data set of center location and labeled > points within a certain range. > Lot's to learn here, that's for > sure. I will file your reply and look at it in a week or so > when I store the first data. > Dennis Gearon > > > > --- On Sun, 7/12/09, Brent Wood <b.wood@xxxxxxxxxx> > wrote: > > > From: Brent Wood <b.wood@xxxxxxxxxx> > > Subject: Re: indexes on float8 vs integer > > To: gearond@xxxxxxxxxxxxx > > Cc: pgsql-general@xxxxxxxxxxxxxx > > Date: Sunday, July 12, 2009, 1:52 PM > > Hi Dennis, > > > > Is there any reason you are not using PostGIS to store > the > > values as point geometries & use a spatial (GIST) > index > > on them? I have tables with hundreds of millions of > point > > features which work well. On disk data volume is not > really > > worth optimising for with such systems, i suggest > > flexibility, ease of implementation & overall > > performance should be more valuable. > > > > If you need to store & query coordinates, then a > map > > based tool seems relevant, and there are plenty of > tools to > > do this soirt of thing with PostGIS data, such as > Mapserver, > > GeoServer at the back end & OpenLayers in the > front > > end. > > > > > > Cheers, > > > > Brent Wood > > > > > > Brent Wood > > DBA/GIS consultant > > NIWA, Wellington > > New Zealand > > >>> Scott Marlowe <scott.marlowe@xxxxxxxxx> > > 07/12/09 10:31 PM >>> > > On Sat, Jul 11, 2009 at 10:15 PM, Dennis Gearon<gearond@xxxxxxxxxxxxx> > > wrote: > > > > > > Anyone got any insight or experience in the speed > and > > size of indexes on Integer(4 byte) vs float (8byte). > For a > > project that I'm on, I'm contemplating using an > integer > > for: > > > > > > Latitude > > > Longitude > > > > > > In a huge, publically searchable table. > > > > > > In the INSERTS, the representation would be equal > to: > > > > > > IntegerLatOrLong = > to_integer( > > float8LatOrLong * to_float(1000000) ); > > > > > > This would keep it in a smaller (4 bytes vs 8 > byte) > > representation with simple numeric comparison for > indexing > > values while still provide 6 decimals of precision, > i.e. > > 4.25 inches of resolution, what google mapes > provides. > > > > > > I am expecting this table to be very huge. Hey, I > want > > to be the next 'portal' :-) > > > Dennis Gearon > > > > Well, floats can be bad if you need exact math or > matching > > anyway, and > > math on them is generally slower than int math. > OTOH, > > you could look > > into numeric to see if it does what you want. > Used to > > be way slower > > than int, but in recent versions of pgsql it's gotten > much > > faster. > > Numeric is exact, where float is approximate, so if > having > > exact > > values be stored is important, then either using int > and > > treating it > > like fixed point, or using numeric is usually better. > > > > -- > > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > > To make changes to your subscription: > > http://www.postgresql.org/mailpref/pgsql-general > > > > NIWA is the trading name of the National Institute of > Water > > & Atmospheric Research Ltd. > > > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > > NIWA is the trading name of the National Institute of Water > & Atmospheric Research Ltd. > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
