= Welcome to the Users PostGIS Wiki! = Everybody is welcome to contribute to this wiki. * You must login to create new pages and modify existing ones. You can create your own [https://www.osgeo.org/cgi-bin/ldap_create_user.py OSGEO Userid] use your existing one or use the generic one (wiki:wiki). * Please prefix every new page names in this section with "!UsersWiki" in order to easily distinguish them from other Wiki Trac pages. * For a quick overview of how to format page's content [wiki:WikiFormatting see this page]. == What is PostGIS? == PostGIS is an extension to the [http://www.postgresql.org PostgreSQL] object-relational database system that allows [http://en.wikipedia.org/wiki/Geographic_information_system GIS] (Geographic Information System) objects to be stored in the database. PostGIS does for PostgreSQL what Oracle Spatial does for Oracle, ArcSDE does for Microsoft SQL Server/Oracle. == Overview == * [wiki:UsersWikiFeaturesOfPostgis Features of PostGIS] * [http://www.postgresonline.com/journal/index.php?/archives/7-PostGIS-for-geospatial-analysis-and-mapping.html PostGIS as a part of PostgreSQL] (Article)] * [wiki:UsersWikiToolsSupportPostgis Tools that support PostGIS] * [wiki:UsersWikiGallery Gallery] Collection of applications using PostGIS in the backend. * [wiki:UsersWikiPostgreSQLCaseStudies PostgreSQL Case Studies] * [wiki:UsersWikiPostGISHosters PostGIS Hosters] * [http://en.wikipedia.org/wiki/PostGIS PostGIS Wikipedia entry] * [wiki:UsersWikiPostgisarcgis PostGIS and ArcSDE/ArcGIS 9.3 Articles] == Compilation and Installation Guides == * Directions for [wiki:UsersWikiPostgisRpmInstallation PostGIS RPM Installation]. * Directions for [wiki:UsersWikiPostgisOnUbuntu PostGIS on Ubuntu]. * Directions for [wiki:UsersWikiWinCompile Compiling in Windows]. == Examples of Spatial SQL == * [wiki:UsersWikiExamplesFindNearby Find Nearby Features] * [wiki:UsersWikiExamplesAntiNear Find Features far from nearest neighbor - Anti-Near Neighbor] * [wiki:UsersWikiExamplesJoinTables Join Spatial and Non-Spatial Tables] * [wiki:UsersWikiExamplesOverlayTables Overlay Geometries in one table with Geometries in another] * [wiki:UsersWikiExamplesInsidePolygon Find Features Inside a Particular Polygon] * [wiki:UsersWikiCleanPolygons Clean Invalid Polygon Topology] * [wiki:UsersWikiExamplesInsidePolygon2 Find points on interior rings within a certain distance to exterior ring] * [wiki:UsersWikiSplitPolygonWithLineString Splitting a Polygon with a Linestring] * [wiki:UsersWikiGenerateHexagonalGrid Generating a hexagonal grid] * [wiki:UsersWikiComputeMultiCentroid MultiPoint centroids from Multi geometries] * [wiki:UsersWikiOGR Examples OGR Examples] == Extending PostGIS == * [wiki:UsersWikiSpatialEJB3 PostGIS EJB3 Integration] * [wiki:UsersWikiPostgisTopology Postgis Topology] - to be moved somewhere else ;) * [wiki:UsersWikiRasterNotes Raster support] * [wiki:WKTRaster WKT Raster] - The new proposed raster implementation in PostGIS * [http://simon.benjamin.free.fr/pgchip/ PGCHIP] - The GDAL Postgis driver for raster data - a corrected version can be found in current GDAL CVS * [wiki:UsersWikiWishList WishList] of features for the future * [wiki:UsersWikiSprint2009Notes Code Sprint 2009 Notes] == Newbie Common Problems and Questions == * [wiki:UsersWikiNewbieAddgeometrycolumn function addgeometrycolumn("unknown", "unknown", integer, "unknown", integer) does not exist] * [wiki:UsersWikiNewbieDistanceMeasurement What is the measurement returned by ST_Distance?] * [wiki:UsersWikiNewbiePostGISFunctionMeasurement What unit of measurement do PostGIS functions use?] * [wiki:UsersWikiNewbieMeasurementInMeters How to get distance measurement in meters?] == Extras == * [wiki:UsersWikiTiger Geocoder TigerGeocoder] == Notes == * [wiki:UsersWikiSpatialAlgorithmWebSites Spatial Algorithm Web Sites] == Useful Additional PL/PGSQL Functions == * [wiki:UsersWikiplpgsqlfunctions PL/PGSQL Functions] * [wiki:UsersWikiNearest Neighbor Search Nearest Neighbor Search] * [wiki:UsersWikiCascadeUnion PL/PGSQL Pseudo Cascade Union Aggregate Function] == What is GEOS == [http://geos.osgeo.org GEOS] is a C++ port of the JTS Topology Suite. It is used by PostGIS to implement Topological functions.