Index: /branches/bills_081204/dbconfig/changes.txt
===================================================================
--- /branches/bills_081204/dbconfig/changes.txt	(revision 20966)
+++ /branches/bills_081204/dbconfig/changes.txt	(revision 20967)
@@ -1309,10 +1309,16 @@
 ALTER TABLE magicDSRun ADD COLUMN cam_id BIGINT AFTER stage_id;
 
---  Version: 1.1.47 is this correct?
-
+--  Version: 1.1.47
+
+-- WARNING WARNING WARNING
+-- Updating a database which has populated diffRun's requires editing
+-- the contents of the tables in a way that cannot be expresed here.
+-- The script tools/collapsdiffinputs.pl does the appropriate edits
+-- and should be run at the spot indicated below
 
 -- fix order of workdir to match pxadmin_create_tables.sql
 ALTER TABLE diffRun CHANGE COLUMN workdir workdir VARCHAR(255) AFTER state;
 
+-- add exposure id to diffRun
 ALTER TABLE diffRun ADD COLUMN exp_id BIGINT;
 ALTER TABLE diffRun ADD FOREIGN KEY (exp_id) REFERENCES rawExp(exp_id);
@@ -1328,5 +1334,10 @@
 ALTER TABLE diffInputSkyfile CHANGE COLUMN skycell_id skycell_id VARCHAR(64) AFTER diff_id;
 
--- run script collapse_diffinputs.pl 
+-- WARNING WARNING
+-- If you have existing diff runs they must be converted
+
+-- run the script collapse_diffinputs.pl here.
+--        collapse_diffinputs.pl dbname dbuser dbpass dbhost
+
 DELETE FROM diffInputSkyfile where template = 1;