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PostGIS - Geographic Information Systems Extensions to PostgreSQL ================================================================= :Version: 2.0.0rc2 :Date: 2012-04-01 :Website: http://postgis.org This distribution contains a module which implements GIS simple features, ties the features to R-tree indexing, and provides many spatial functions for accessing and analyzing geographic data. Directory structure:: ./ Build scripts and install directions ./doc PostGIS Documentation ./extensions Support for the PostgreSQL 9.1+ Extensions framework ./extras Various pieces that didn't belong to mainstream (package management specfiles, WFS_locks, sample WKB parser) ./java/ejb EJB Java support ./java/jdbc Extensions to the PostgreSQL JDBC drivers to support the GIS objects ./java/pljava PostgreSQL PL/Java spatial object support ./liblwgeom LWGEOM geometry library ./libpgcommon PostGIS library to bridge LWGEOM to PostgreSQL ./loader A program to convert ESRI Shape files into SQL text suitable for uploading into a PostGIS/PostgreSQL database and a program for converting PostGIS spatial tables into shapefiles ./postgis PostGIS library source code ./raster PostGIS rasters extension source code ./regress Online regression tests ./topology PostGIS topology extension source code ./utils Utility scripts for PostGIS (upgrade, profiling, ...) REQUIREMENTS ------------ PostGIS is compatible with PostgreSQL 8.4 and above. You *must* have the full PostgreSQL - including server headers - installed for this to work. * PROJ4 (Required, Version 4.6.0 or higher): The PROJ4 catographic projection library is required if you want to use the ST_Transform() function to reproject features within the database. http://trac.osgeo.org/proj/ * GEOS (Required, Version 3.2.2 or higher): The GEOS library provides support for exact topological tests such as ST_Touches(), ST_Contains(), ST_Disjoint() and spatial operations such as ST_Intersection(), ST_Union() and ST_Buffer(). GEOS 3.3.2 or higher is recommended. http://trac.osgeo.org/geos/ * XML SUPPORT (Required, Version 2.5.0 or higher): The LibXML2 library is required to use the ST_GeomFromGML() and ST_GeomFromKML() functionality. http://xmlsoft.org/ * GNU gettext The loader, and hence PostGIS, requires GNU gettext 0.14 or higher (typically in libc on GNU/Linux, in which case 0.17 is required). * JSON-C (Required, Version 0.9 or higher) JSON-C is used to import GeoJSON via the function ST_GeomFromGeoJson(). http://oss.metaparadigm.com/json-c/. You can get it installed in apt-based systems using:: apt-get install libjson0-dev * GDAL (Optional, Version 1.6.0 or higher) GDAL (http://gdal.org) is *required* if you want to compile PostGIS with raster support. To compile without raster support you must ``./configure --without-raster`` CONFIGURATION ------------- To configure PostGIS, run:: ./configure The results of the configuration can be easily seen within the ``postgis_config.h`` file. If ``pg_config`` can't be found in your ``$PATH`` configure will complain and refuse to proceed. You can specify it using the ``--with-pgconfig=/path/to/pg_config`` flag. If PROJ4 has been installed but cannot be found, configure will complain and refuse to proceed. You can specify an alternative installation directory using the ``--with-projdir=DIR`` option. If GEOS has been installed but cannot be found, configure will complain and refuse to proceed. You can specify an alternative ``geos-config`` file using the ``--with-geosconfig=/path/to/geos-config`` option. If GDAL cannot be found, configure will complain and refuse to proceed. You can either procede without raster support using ``--without-raster`` or use ``--with-gdalconfig=/path/to/gdal-config`` option. By default, both Topology and Raster extensions are enabled in ``./configure``. If you want to compile PostGIS *without* Raster support, you must provide the ``--without-raster`` option. If you want to compile PostGIS *without* Topology support, you must provide the ``--without-topology`` option. See ``./configure --help`` for more options. BUILD ----- PostGIS uses the GNU make (aka gmake) for building. To build PostGIS library and utilities, as postgres run:: make TESTING ------- You want to run regress tests before installation. To do so, as postgres run:: make check The above will create a test database with PostGIS extensions, run tests and then drop the test database. Final lines of output contain a summary of test results: run, succeeded, failed. If you have any failure please file a bug report using the online bug tracker: http://trac.osgeo.org/postgis/report/3 INSTALLATION ------------ To install PostGIS library and utilities, as postgres run:: make install Installation paths will typically be derived by ``pg_config``: - Lib in ``pg_config --pkglibdir`` - Binaries (loader/dumper) in ``pg_config --bindir`` - Important support files in ``[prefix]/share/contrib`` - Manual pages in ``[prefix]/man`` - Documentation in in ``[prefix]/share/doc`` Where `[prefix]` above is extracted from ``pg_config --configure``. You can change them using ``./configure`` switches. See CONFIGURATION section. CREATING NEW SPATIAL DATABASES ------------------------------ PostGIS support must be enabled for each database that requires its usage. This is done by feeding the ``postgis.sql`` (the enabler script) file to the target database. The enabler script requires the PL/pgSQL procedural language in order to operate correctly, you can use the ``createlang`` program from the PostgreSQL installation. (The PostgreSQL Programmer's Guide has details if you want to do this manually for some reason.) So, as postgres run:: createlang plpgsql <yourdatabase> psql -f postgis/postgis.sql -d <your_database> Your database should now be spatially enabled. ADDING RASTER SUPPORT TO A SPATIAL DATABASE ------------------------------------------- To enable raster support you must first load the ``postgis.sql`` file. You can then load the ``rtpostgis.sql`` file. psql -f postgis/rtpostgis.sql -d <your_database> UPGRADING EXISTING SPATIAL DATABASES ------------------------------------ Upgrading existing spatial databases can be tricky as it requires replacement or introduction of new PostGIS object definitions. Unfortunately not all definitions can be easily replaced in a live database, so sometimes your best bet is a dump/reload process. PostGIS provides a SOFT UPGRADE procedure for minor or bugfix releases, and an HARD UPGRADE procedure for major releases. SOFT UPGRADE ~~~~~~~~~~~~ Soft upgrade consists of sourcing the ``postgis_upgrade_*.sql`` script in your spatial database: * ``postgis_upgrade_13_to_15.sql``, upgrade a 1.3.x database to 1.5 * ``postgis_upgrade_15_to_15.sql``, upgrade a 1.4.x database to 1.5 * ``postgis_upgrade_16_minor.sql``, upgrade a 1.5.x database to the latest minor release If a soft upgrade is not possible the script will abort and no harm will be done. You can then move on to the HARD UPGRADE process. Always try a soft upgrade first; they are much simpler. HARD UPGRADE ~~~~~~~~~~~~ Hard upgrade is a PostgreSQL dump/restore procedure combined with a filter to selectively update PostGIS functions and objects to point to a new library version. Hard upgrades are required when object definitions have changed, aggregates have changed or been added, and when the underlying PostgreSQL database itself has undergone a major update. For this purpose, PostGIS provides a utility script to restore a dump in "custom" format. The hard upgrade procedure is as follows:: #  Create a "custom-format" dump of the database you want # to upgrade (let's call it "olddb") $ pg_dump -Fc -f olddb.dump olddb #  Do a fresh install of PostGIS in a new database # (let's call it "newdb"). # Refer to CREATING NEW SPATIAL DATABASES for instructions #  Restore the dump into your new database. $ perl utils/postgis_restore.pl -v olddb.dump \ 2> restore.log | psql newdb 2> errors.log The ``spatial_ref_sys`` entries found in your dump will be restored, but they will not override existing ones in ``spatial_ref_sys``. This is to ensure that fixes in the official set will be properly propagated to restored databases. If for any reason you really want your own overrides of standard entries just don't load the ``spatial_ref_sys.sql`` file when creating the new database. If your database is really old or you know you've been using long deprecated functions in your views and functions, you might need to load ``legacy.sql`` before restoring the dump for all your functions and views etc. to properly come back. Only do this if *really* needed. Consider upgrading your views and functions before dumping instead, if possible. The deprecated functions can be later removed by loading ``uninstall_legacy.sql``. USAGE ----- Try the following example SQL statements to create non-OpenGIS tables and geometries:: CREATE TABLE geom_test ( gid int4, geom geometry, name varchar(25) ); INSERT INTO geom_test ( gid, geom, name ) VALUES ( 1, 'POLYGON((0 0 0,0 5 0,5 5 0,5 0 0,0 0 0))', '3D Square'); INSERT INTO geom_test ( gid, geom, name ) VALUES ( 2, 'LINESTRING(1 1 1,5 5 5,7 7 5)', '3D Line' ); INSERT INTO geom_test ( gid, geom, name ) VALUES ( 3, 'MULTIPOINT(3 4,8 9)', '2D Aggregate Point' ); SELECT * from geom_test WHERE geom && 'BOX3D(2 2 0,3 3 0)'::box3d; The following SQL creates proper OpenGIS entries in the ``SPATIAL_REF_SYS`` and ``GEOMETRY_COLUMNS`` tables, and ensures that all geometries are created with an SRID:: INSERT INTO SPATIAL_REF_SYS ( SRID, AUTH_NAME, AUTH_SRID, SRTEXT ) VALUES ( 1, 'EPSG', 4269, 'GEOGCS["NAD83", DATUM[ "North_American_Datum_1983", SPHEROID[ "GRS 1980", 6378137, 298.257222101 ] ], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]]' ); CREATE TABLE geotest ( id INT4, name VARCHAR(32) ); SELECT AddGeometryColumn('db', 'geotest', 'geopoint', 1, 'POINT', 2); INSERT INTO geotest (id, name, geopoint) VALUES (1, 'Olympia', ST_GeomFromText('POINT(-122.90 46.97)', 1)); INSERT INTO geotest (id, name, geopoint) VALUES (2, 'Renton', ST_GeomFromText('POINT(-122.22 47.50)', 1)); SELECT name, AsText(geopoint) FROM geotest; Spatial Indexes ~~~~~~~~~~~~~~~ PostgreSQL provides support for GiST spatial indexing. The GiST scheme offers indexing even on large objects, using a system of "lossy" indexing where a large object is proxied by a smaller one in the index. In the case of the PostGIS indexing system, all objects are proxied in the index by their bounding boxes. You can build a GiST index with:: CREATE INDEX <indexname> ON <tablename> USING GIST ( <geometryfield> ); Always run the ``VACUUM ANALYZE <tablename>`` on your tables after creating an index. This gathers statistics which the query planner uses to optimize index usage. PostGIS Topology support ~~~~~~~~~~~~~~~~~~~~~~~~ See topology/README for more informations about topology support.