My recent blog entry about pg_upgrade improvements in Postgres 9.2 prompted a community discussion about the time-consuming requirement of generating optimizer statistics once pg_upgrade completes. This requirement makes pg_upgrade less useful because it delays the server from being put into production. The agreed solution was to have pg_upgrade create a script that generates increasingly more-accurate statistics — this allows the new cluster to be available in minutes, with full statistics taking perhaps an hour or more to complete.
Fortunately, the script created automatically by pg_upgrade in Postgres 9.2 works just fine in earlier versions of Postgres, so I am supplying links (Unix, Windows) for users who are currently using pg_upgrade. (Those upgrading from Postgres 8.3 will need to change the final "--analyze-only" to "--analyze"; pg_upgrade automatically handles this when it creates the script.) I hope this helps, and I am interested in feedback about the script's effectiveness.