Stephen Frost <sfrost@snowman.net> wrote:
> If it's not actually *changing* (wrt its value), then I'm not at
> all impressed with the notion that it's going to get updated
> anyway.
But PostgreSQL very specifically (and as far as I can tell
*intentionally*) allows you to *change* a value and have it still
be considered *equal*. The concept of equal values really means
more like "equivalent" or "close enough" for common purposes. It
very specifically does *not* mean the same value.
As just one example, think how much easier the citext type would be
to implement if it folded all values to lower case as they were
input, rather than preserving the data as entered and considering
different capitalizations as "equal".
The notion that in PostgreSQL a value has not changed if the new
value is equal to the old is just flat out wrong.
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company