> The key to understanding the problem is to realize that system
> catalogs are pretty much regular tables in PostgreSQL, with some
> additional special rules (no triggers, can't be CLUSTERed or ALTERed,
> &c). Anything you'd do in a regular table that would create a dead
> tuple UPDATEs, DELETEs, &c will have the same effect on a catalog.
Thanks for the detailed explanation on this topic.
