Itemize some issues with restoring data from old that cause failures

git-svn-id: http://svn.osgeo.org/postgis/trunk@7522 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/MIGRATION b/MIGRATION
index e558c02b7cd59b13861861e2a06521bd3c09aa5a..a2efc71bbed838c3d884ea65822a66efe115888e 100644 (file)
--- a/MIGRATION
+++ b/MIGRATION
@@ -31,5 +31,23 @@ a table to a view.
     that the geometry type strings will be mixed case and include the
     dimensionality modifiers. For example: PointZM, MultiLineStringZ.
 
+    
+Restoring data from prior versions -- GOTCHAS
+-----------------------------------------------
+The populate_geometry_columns() function in PostGIS 1.5 and below, used the deprecated functions
+ndims() and srid() for defining constraints.  As a result these tables will not restore into a fresh PostGIS 2.0 database unless you
 
+1) Drop these contraints before you restore the data
 
+or 
+
+2) Install the legacy functions srid() and ndims() found in the legacy.sql file before you try to restore these tables.
+
+Function is not unique after restore
+-------------------------------------
+After you restore old data into a fresh PostGIS 2.0 database, YOU MUST install the uninstall_legacy.sql
+file after the restore.  If you don't you will run into "function is not unique" errors in your applications.
+The other issue with having the old functions is the old functions you restore will be bound to the old postgis library which is incompatible with the
+new postgis geometry structures.
+
+If you still require legacy functions, you can install the legacy.sql file after the uninstall_legacy.sql.
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