When doing database work over the web, especially when many records are
on one page, *many* updates get posted to pg that do not change the
record. Eg, the page may contain 50 records, the user changes 1, and
submits.
I assume that a no-change update takes the same resources as a real
update,
One strategy is to use some sort of middleware that takes care of this. On
a project I did a few years ago, I used a perl module that read the record
from Postgres and made it into a perl object. The object contained a
variable, changed, that reflected whether anything had actually changed
in the
