On 2015-04-23 15:40:36 -0400, Robert Haas wrote:
> The issue is that you have to vacuum a table frequently enough to
> avoid accumulating bloat. The frequency with which you need to vacuum
> varies depending on the size of the table and how frequently it's
> updated. However, a large, heavily-updated table can take long enough
> to vacuum that, by the time you get done, it's already overdue to be
> vacuumed again. That's a problem.
Especially because the indexes are scanned fully. In many cases I've
observed the heap scans themselves being fast; but scanning hundreds
(yes) of gigabytes of indexes taking ages.
Andres
