On Fri, 2003-09-05 at 10:01, Stephan Szabo wrote:
> This is the section in create function reference page about immutable. I'd
> thought it was clear, but do you have a better suggested wording?
While we're on the subject, this adjacent paragraph of the docs seems
unclear:
STABLE indicates that within a single table scan the function
will consistently return the same result for the same argument
values, but that its result could change across SQL statements.
This is the appropriate selection for functions whose results
depend on database lookups, parameter variables (such as the
current time zone), etc. Also note that the current_timestamp
family of functions qualify as stable, since their values do not
change within a transaction.
So, can a STABLE function change across SQL statements (as the beginning
of the paragraph implies), or across transactions (as the end of the
paragraph implies)?
-Neil