Added section on upgrading.

git-svn-id: http://svn.osgeo.org/postgis/trunk@42 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/README.postgis b/README.postgis
index 4c5b6508c52be1d5c6bd4d612e3863b917d4d0f6..b34dccd20f29e888eff0b2fe3b29f8f1cb62dc2c 100644 (file)
--- a/README.postgis
+++ b/README.postgis
@@ -47,6 +47,22 @@ To run some regression tests, use 'make test'. The results will be output
 to tests/output.log and compared to tests/expected.log.
 
 
+UPGRADING:
+
+Upgrading PostGIS can be tricky, because the underlying C libraries which 
+support the object types and geometries may have changed between versions.
+To avoid problems when upgrading, you will have to dump all the tables
+in your database, destroy the database, create a new one, upload the
+new postgis.sql file, then upload your database dump:
+
+        pg_dump -t "*" -f dumpfile.sql yourdatabase
+        dropdb yourdatabase
+        createdb yourdatabase
+        psql -f postgis.sql -d yourdatabase
+        psql -f dumpfile.sql -d yourdatabase
+       vacuumdb -z yourdatabase
+
+
 USAGE:
 
 Try the following example SQL statements: