Thread: spatial index
hi - a very simple question from a newbie. Im tyring to outdo my colleagues Perl code (running on the same machine) for spatialoperations (point-in-poly) but on a vanilla install of postgres 7.1 his perl is 20 times faster!! Ive no spatial indexbuilt on the polygon but I cant get one built as it complains of a tuple_row error which i assume relates to the useof the default 8Kb block size - my question is - how do I rebuild with a bigger block size so as I can build an rtreeon the poly? (or can someone give me some idea of how postgres spatial operations perform relative to other solutions- Id like to employ postgres for a gazetteer service but I need to get the speed of response up....any ideas/thoughtsappreciated) +----------------------------------------------------------------------------------------+ ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸ James S Reid, National Service Coordinator UKBORDERS EDINA , Tel: +44 0131 651 1383 Data Library, Fax: +44 0131 650 3308 Main Library, Edinburgh University, Edinburgh EH8 9LJ, E-mail: James.Reid@ed.ac.uk Scotland. Internet: edina.ed.ac.uk/ukborders/ ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸ +------------------------------------------------------------------------------------------+
On Thu, 29 Nov 2001, James Reid wrote: > hi - a very simple question from a newbie. Im tyring to outdo my colleagues Perl code (running on the same machine) forspatial operations (point-in-poly) but on a vanilla install of postgres 7.1 his perl is 20 times faster!! Ive no spatialindex built on the polygon but I cant get one built as it complains of a tuple_row error which i assume relates tothe use of the default 8Kb block size - my question is - how do I rebuild with a bigger block size so as I can build anrtree on the poly? (or can someone give me some idea of how postgres spatial operations perform relative to other solutions- Id like to employ postgres for a gazetteer service but I need to get the speed of response up....any ideas/thoughtsappreciated) [ Sorry, I'm not going to reformat his paragraph. ] Are you running 7.1? That gets around some of the tuple size issues. There is a Spatial DBase add-on to PostgreSQL called PostGIS (?). You might want to look around the OpenGIS consortium website to get info on this, and other spatial oriented things. Gord Matter Realisations http://www.materialisations.com/ Gordon Haverland, B.Sc. M.Eng. President 101 9504 182 St. NW Edmonton, AB, CA T5T 3A7 780/481-8019 ghaverla @ freenet.edmonton.ab.ca 780/993-1274 (cell)
James Reid <james.reid@ed.ac.uk> writes: > [ how to do a spatial index ] Take a look at PostGIS, http://postgis.refractions.net. Not sure that you want everything in there, but their approaches to indexing might be useful. BTW, there are nontrivial bug fixes for both rtree and gist index types in 7.2, so you might want to run on latest 7.2 beta rather than 7.1. regards, tom lane