> If you are updating a large portion of your tree, you will probably want to throw in a vacuum in
> between the two updates. This should reduce the bloat caused by dead tuples in both your index
> and table.
... but that will only work if you can commit the first set of changes
before you get to the end result, possibly having an inconsistent state
for the duration of the vacuum... if you want all in one transaction,
vacuum will not help.
Cheers,
Csaba.
