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diff --git a/databases/postgis/files/README.postgis b/databases/postgis/files/README.postgis new file mode 100644 index 000000000000..12163a476453 --- /dev/null +++ b/databases/postgis/files/README.postgis @@ -0,0 +1,214 @@ +PostGIS - Geographic Information Systems Extensions to PostgreSQL +~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +VERSION: 1.0.0 (2005/01/13) + +MORE INFORMATION: http://postgis.refractions.net + +INTRODUCTION: +This distribution contains a module which implements GIS simple +features, ties the features to rtree indexing, and provides some +spatial functions for accessing and analyzing geographic data. + +Directory structure: + + ./ Build scripts and install directions. + ./lwgeom Library source code. + ./jdbc Extensions to the PostgreSQL JDBC drivers to support + the GIS objects. + ./doc Documentation on the code, objects and functions + provided. + ./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 + Shape files.. + ./examples Small programs which demonstrate ways of accessing + GIS data. + + +INSTALLATION: + +PostGIS is compatible with PostgreSQL 7.2 and above. + +To install the module, move this directory to the "contrib" directory of your +PostgreSQL source installation. Alternately, point PGSQL_SRC at your +PostgreSQL source tree either in an environment variable or editing +Makefile.config. + +You *must* have a PostgreSQL source tree, and you *must* have succesfully +built and installed it for this to work. + +SEE THE NOTE ON GEOS SUPPORT BELOW FOR SPECIAL COMPILATION INSTRUCTIONS + + +* PROJ4 SUPPORT (Recommended): + The Proj4 reprojection library is required if you want to use the + transform() function to reproject features within the database. + + http://www.remotesensing.org/proj + + Install Proj4 in the default location. + Edit the postgis Makefile.config and change the USE_PROJ variable to 1 + and ensure that the PROJ_DIR variable points to your Proj4 + installation location (/usr/local is the default). + +* SPATIAL PREDICATE / GEOS SUPPORT (Recommended): + The GEOS library provides support for exact topological tests + such as Touches(), Contains(), Disjoint() and spatial operations + such as Intersection(), Union() and Buffer(). + + http://geos.refractions.net + + In order to use the GEOS support, you *may* need to specially compile + your version of PostgreSQL to link the C++ runtime library. + To do this, invoke the PgSQL configuration script this way: + + LDFLAGS=-lstdc++ ./configure --your-options-go-here + + The initial LDFLAGS variable is passed through to the Makefile and + adds the C++ library to the linking stage. + Once you have compiled PgSQL with C++ support, you can enable GEOS + support in PostGIS by setting the USE_GEOS variable in the PostGIS + Makefile.config to 1, and ensure that the GEOS_DIR variable points + to your GEOS installation location (/usr/local is the default). + + +To compile PostGIS, as root run: + + make + make install + +PostGIS now requires the PL/pgSQL procedural language in order to operate +correctly. To install PL/pgSQL use the 'createlang' program from the PostgreSQL +installation. (The PostgreSQL Programmer's Guide has details if you want +to this manually for some reason.) + +As postgres run: + + createlang plpgsql yourdatabase + psql -f lwpostgis.sql -d yourdatabase + +Installation should now be complete. + + +UPGRADING: + +Upgrading PostGIS can be tricky, because the underlying C libraries which +support the object types and geometries may have changed between versions. + +For this purpose PostGIS provides an utility script to restore a dump +produced with the pg_dump -Fc command. It is experimental so redirecting +its output to a file will help in case of problems. The procedure is +as follow: + + # Create a "custom-format" dump of the database you want + # to upgrade (let's call it "olddb") + $ pg_dump -Fc olddb olddb.dump + + # Restore the dump contextually upgrading postgis into + # a new database. The new database doesn't have to exist. + # Let's call it "newdb" + $ sh utils/postgis_restore.pl lwpostgis.sql newdb olddb.dump > restore.log + + # Check that all restored dump objects really had to be restored from dump + # and do not conflict with the ones defined in lwpostgis.sql + $ grep ^KEEPING restore.log | less + + # If upgrading from PostgreSQL < 7.5 to >= 7.5 you might want to + # drop the attrelid, varattnum and stats columns in the geometry_columns + # table, which are no-more needed. Keeping them won't hurt. + # !!! DROPPING THEM WHEN REALLY NEEDED WILL DO HURT !!!! + $ psql newdb -c "ALTER TABLE geometry_columns DROP attrelid" + $ psql newdb -c "ALTER TABLE geometry_columns DROP varattnum" + $ psql newdb -c "ALTER TABLE geometry_columns DROP stats" + + # spatial_ref_sys table is restore from the dump, to ensure your custom + # additions are kept, but the distributed one might contain modification + # so you should backup your entries, drop the table and source the new one. + # If you did make additions we assume you know how to backup them before + # upgrading the table. Replace of it with the new one is done like this: + $ psql newdb + newdb=> drop table spatial_ref_sys; + DROP + newdb=> \i spatial_ref_sys.sql + +Following is the "old" procedure description. IT SHOULD BE AVOIDED if possible, +as it will leave in the database many spurious functions. It is kept in this document +as a "backup" in case postgis_restore.pl won't work for you: + + pg_dump -t "*" -f dumpfile.sql yourdatabase + dropdb yourdatabase + createdb yourdatabase + createlang plpgsql yourdatabase + psql -f lwpostgis.sql -d yourdatabase + psql -f dumpfile.sql -d yourdatabase + vacuumdb -z yourdatabase + + +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', GeometryFromText('POINT(-122.90 46.97)',1)); + INSERT INTO geotest (id, name, geopoint) + VALUES (2, 'Renton', GeometryFromText('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. + |