Melvin Davidson <melvin6925(at)gmail(dot)com> writes:
> Also, don't forget to test for relkind = 'r'. My bad from before.
In principle you need to ignore attisdropped columns as well.
Thinking about Jim's point about speed: it'd be wise to collapse any
updates for multiple columns in the same table into one ALTER command,
so that you only rewrite the table once, not once per column.
regards, tom lane