Index: ext/ota/sqlite3ota.h
==================================================================
--- ext/ota/sqlite3ota.h
+++ ext/ota/sqlite3ota.h
@@ -186,10 +186,16 @@
 **
 ** causes a result similar to:
 **
 **   UPDATE ft1 SET b = 'usa' WHERE rowid = 12;
 **
+** The data_xxx tables themselves should have no PRIMARY KEY declarations.
+** However, OTA is more efficient if reading the rows in from each data_xxx
+** table in "rowid" order is roughly the same as reading them sorted by
+** the PRIMARY KEY of the corresponding target database table. In other 
+** words, rows should be sorted using the destination table PRIMARY KEY 
+** fields before they are inserted into the data_xxx tables.
 **
 ** USAGE
 **
 ** The API declared below allows an application to apply an OTA update 
 ** stored on disk to an existing target database. Essentially, the